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1.
Electrophoresis ; 38(9-10): 1344-1352, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28261824

RESUMEN

mAbs are currently mainstream in biopharmaceuticals, and their market has been growing due to their high target specificity. Characterization of heterogeneities in mAbs is performed to secure their quality and safety by physicochemical analyses. However, they require time-consuming task, which often strain the resources of drug development in pharmaceuticals. Rapid and direct method to determine the heterogeneities should be a powerful tool for pharmaceutical analysis. Considering the advantages of electrophoresis and MS, this study addresses the combination of SDS-PAGE and intact mass analysis, which provides direct, rapid, and orthogonal determination of heterogeneities in mAb therapeutics. mAb therapeutics that migrated in SDS-PAGE were recovered from gel by treatment with SDC-containing buffer. Usage of SDC-containing buffer as extraction solvent and ethanol-based staining solution enhanced the recovery of intact IgG from SDS-PAGE gels. Recovery of mAbs reached more than 86% with 0.2% SD. The heterogeneities, especially N-glycan variants in the recovered mAb therapeutics, were clearly determined by intact mass analysis. We believe that the study is important in pharmaceuticals‧ perspective since orthogonal combination of gel electrophoresis and intact mass analysis should be pivotal role for rapid and precise characterization of mAbs.


Asunto(s)
Anticuerpos Monoclonales/química , Cromatografía Líquida de Alta Presión/métodos , Electroforesis en Gel de Poliacrilamida/métodos , Polisacáridos/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Anticuerpos Monoclonales/análisis , Polisacáridos/análisis
2.
Glycoconj J ; 33(3): 405-415, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26511985

RESUMEN

The Human Disease Glycomics/Proteome Initiative (HGPI) is an activity in the Human Proteome Organization (HUPO) supported by leading researchers from international institutes and aims at development of disease-related glycomics/glycoproteomics analysis techniques. Since 2004, the initiative has conducted three pilot studies. The first two were N- and O-glycan analyses of purified transferrin and immunoglobulin-G and assessed the most appropriate analytical approach employed at the time. This paper describes the third study, which was conducted to compare different approaches for quantitation of N- and O-linked glycans attached to proteins in crude biological samples. The preliminary analysis on cell pellets resulted in wildly varied glycan profiles, which was probably the consequence of variations in the pre-processing sample preparation methodologies. However, the reproducibility of the data was not improved dramatically in the subsequent analysis on cell lysate fractions prepared in a specified method by one lab. The study demonstrated the difficulty of carrying out a complete analysis of the glycome in crude samples by any single technology and the importance of rigorous optimization of the course of analysis from preprocessing to data interpretation. It suggests that another collaborative study employing the latest technologies in this rapidly evolving field will help to realize the requirements of carrying out the large-scale analysis of glycoproteins in complex cell samples.


Asunto(s)
Glicómica/métodos , Espectrometría de Masas/métodos , Técnicas de Diagnóstico Molecular/métodos , Polisacáridos/química , Biomarcadores/química , Línea Celular Tumoral , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Líquida de Alta Presión/normas , Glicómica/normas , Glicoproteínas/química , Humanos , Espectrometría de Masas/normas , Técnicas de Diagnóstico Molecular/normas , Proteómica/métodos , Proteómica/normas , Reproducibilidad de los Resultados
3.
Yakugaku Zasshi ; 134(11): 1209-17, 2014.
Artículo en Japonés | MEDLINE | ID: mdl-25366918

RESUMEN

Carboxymethyl cellulose (CMC) is one of the most important cellulose derivatives and used in the fields of food, pharmaceuticals, cosmetics, and paint. Fibrous CMC is used an antiadhesive material to prevent postoperative wound adhesions. The degree of substitution and distribution of the substituent (i.e., the carboxymethyl group) are the most important parameters for the function of CMC. Thus, CMC used for antiadhesive material must be carefully evaluated, because the CMC product is retained in patients' bodies over the long term. Although identification tests of CMC are defined in the Japanese Pharmacopoeia, it is difficult to evaluate its structure using those tests. In the present study, we propose improved methods for evaluating CMC products by analyzing monosaccharides after hydrolysis.


Asunto(s)
Carboximetilcelulosa de Sodio/química , Cromatografía Liquida , Humanos , Espectrometría de Masas , Reproducibilidad de los Resultados , Adherencias Tisulares
4.
Methods Mol Biol ; 1200: 131-46, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25117231

RESUMEN

Capillary affinity electrophoresis (CAE) is a powerful technique for glycan analysis, and one of the analytical approaches for analyzing the interaction between lectins and glycans. The method is based on the high-resolution separation of fluorescently labeled glycans by capillary electrophoresis (CE) with laser-induced fluorescence detection (LIF) in the presence of lectins (or glycan binding proteins). CAE allows simultaneous determination of glycan structures in a complex mixture of glycans. In addition, we can calculate the binding kinetics on a specific glycan in the complex mixture of glycans with a lectin. Here, we show detailed procedures for capillary affinity electrophoresis of fluorescently labeled glycans with lectins using CE-LIF apparatus. Its application to screening a sialic acid binding protein in plant barks is also shown.


Asunto(s)
Electroforesis Capilar/métodos , Lectinas/metabolismo , Polisacáridos/metabolismo , Animales , Colorantes Fluorescentes/química , Humanos , Cinética , Rayos Láser , Leche/química , Oligosacáridos/metabolismo , Orosomucoide/metabolismo , Polisacáridos/química , Unión Proteica
5.
J Biol Chem ; 289(37): 25833-43, 2014 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-25074924

RESUMEN

Human embryonic stem cells (hESCs) are pluripotent stem cells from early embryos, and their self-renewal capacity depends on the sustained expression of hESC-specific molecules and the suppressed expression of differentiation-associated genes. To discover novel molecules expressed on hESCs, we generated a panel of monoclonal antibodies against undifferentiated hESCs and evaluated their ability to mark cancer cells, as well as hESCs. MAb7 recognized undifferentiated hESCs and showed a diffuse band with molecular mass of >239 kDa in the lysates of hESCs. Although some amniotic epithelial cells expressed MAb7 antigen, its expression was barely detected in normal human keratinocytes, fibroblasts, or endothelial cells. The expression of MAb7 antigen was observed only in pancreatic and gastric cancer cells, and its levels were elevated in metastatic and poorly differentiated cancer cell lines. Analyses of MAb7 antigen suggested that the clustered NeuAcα2-3Galß O-linked oligosaccharides on DMBT1 (deleted in malignant brain tumors 1) were critical for MAb7 binding in cancer cells. Although features of MAb7 epitope were similar with those of TRA-1-60, distribution of MAb7 antigen in cancer cells was different from that of TRA-1-60 antigen. Exposure of a histone deacetylase inhibitor to differentiated gastric cancer MKN74 cells evoked the expression of MAb7 antigen, whereas DMBT1 expression remained unchanged. Cell sorting followed by DNA microarray analyses identified the down-regulated genes responsible for the biosynthesis of MAb7 antigen in MKN74 cells. In addition, treatment of metastatic pancreatic cancer cells with MAb7 significantly abrogated the adhesion to endothelial cells. These results raised the possibility that MAb7 epitope is a novel marker for undifferentiated cells such as hESCs and cancer stem-like cells and plays a possible role in the undifferentiated cells.


Asunto(s)
Diferenciación Celular/genética , Células Madre Embrionarias/metabolismo , Regulación del Desarrollo de la Expresión Génica/inmunología , Oligosacáridos/inmunología , Receptores de Superficie Celular/genética , Anticuerpos Monoclonales/genética , Proteínas de Unión al Calcio , Diferenciación Celular/inmunología , Proteínas de Unión al ADN , Células Madre Embrionarias/citología , Células Endoteliales/metabolismo , Epítopos/inmunología , Fibroblastos/metabolismo , Citometría de Flujo , Humanos , Queratinocitos/metabolismo , Células Madre Neoplásicas/inmunología , Células Madre Neoplásicas/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , Oligosacáridos/genética , Receptores de Superficie Celular/inmunología , Neoplasias Gástricas/genética , Neoplasias Gástricas/inmunología , Neoplasias Gástricas/patología , Proteínas Supresoras de Tumor
6.
Anal Sci ; 30(4): 483-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24717658

RESUMEN

We evaluated the performance of a commercial microchip electrophoresis instrument (LabChip(®) GXII) for the evaluation of change of degradation species of therapeutic antibodies in stability testing. This system requires a sample volume of only 5 µg, and indicates fine resolution of size variant species such as light chain, heavy chain, non-glycosylated heavy chain and various degradation species. Precision and accuracy were high; the intermediate precision of 18 determinations was only 2.1% or less as RSD and recoveries ranged from 97.8 to 103.0% for major species as heavy chain, light chain and intact molecule of a therapeutic antibody. The applicability of this method was demonstrated by applying the method for the analysis of heat-degraded products of three pharmaceutical antibodies. Though some fragment peaks commonly appeared and increased according to temperature regardless of the source of preparations, one of them indicated specific peaks implying the cleavage of the peptide chain of the heavy chain. We also compared the performance of the method with those using conventional capillary-based SDS electrophoresis. Although the absolute purity values expressed as peak area % were different for the two methods, probably due to the difference in the detection methods, similar quality profiles were obtained within 40 s by microchip-based SDS electrophoresis. In addition, the degradation manner of three marketed antibodies depending on temperature was almost the same for the two methods. At the first stage in the development of manufacturing antibody pharmaceuticals, various factors including cell selection, cell cultivation, and formulation development should be evaluated using limited sample amounts. The stability testing using microchip-based electrophoresis seems suitable for these purposes.


Asunto(s)
Anticuerpos Monoclonales/análisis , Electroforesis por Microchip/métodos , Electroforesis en Gel de Poliacrilamida/métodos , Anticuerpos Monoclonales/química , Estabilidad de Medicamentos , Electroforesis por Microchip/instrumentación , Electroforesis en Gel de Poliacrilamida/instrumentación , Dispositivos Laboratorio en un Chip , Peso Molecular , Estabilidad Proteica , Proteolisis , Control de Calidad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Temperatura
7.
Curr Eye Res ; 39(7): 686-94, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24400666

RESUMEN

PURPOSE: We compared cultured Statens Seruminstitut rabbit cornea (SIRC) cells and corneal epithelial cells from rabbit eyes by analyzing their N-glycans and glycosaminoglycans (GAGs). This work is a fundamental study on the efficacy of using cultured cells instead of animals for drug development. MATERIALS AND METHODS: N-Glycans and GAGs from SIRC cell monolayers and corneal epithelial cells of rabbit eyes were analyzed by capillary electrophoresis (CE) and a combination of high-performance liquid chromatography (HPLC) and mass spectrometry. RESULTS: High mannose-type glycans and a hybrid-type glycan were the common N-glycans in SIRC cells and corneal epithelial cells of rabbit eyes. Mono-fucosylated biantennary glycans with or without one N-acetylneuraminic acid residue were observed only in SIRC cells. Hyaluronic acid was the only measurable GAG in the corneal epithelial cells of rabbit eyes. In contrast, hyaluronic acid and chondroitin sulfates were abundantly present in SIRC cells. CONCLUSIONS: Profiles of both N-glycans and GAGs were conspicuously different between SIRC cells and corneal epithelial cells of rabbit eyes. This report will be useful for the evaluation of pharmaceutical candidates when animals or cultured cells are employed in drug development studies.


Asunto(s)
Córnea/química , Glicosaminoglicanos/metabolismo , Animales , Transporte Biológico , Línea Celular , Cromatografía de Afinidad , Cromatografía Líquida de Alta Presión , Córnea/citología , Electroforesis Capilar , Epitelio Corneal/química , Epitelio Corneal/citología , Polisacáridos/química , Polisacáridos/metabolismo , Conejos
8.
J Proteome Res ; 13(2): 1021-33, 2014 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-24354860

RESUMEN

Recently, we reported comparative analysis of glycoproteins which express cancer-specific N-glycans on various cancer cells and identified 24 glycoproteins having polylactosamine (polyLacNAc)-type N-glycans that are abundantly present in malignant cells [ Mitsui et al., J. Pharm. Biomed. Anal. 2012 , 70 , 718 - 726 ]. In the present study, we applied the technique to comparative studies on common glycoproteins present in the matched patient primary and metastatic melanoma cell lines. Metastatic melanoma cells (WM266-4) contained a large amount of polyLacNAc-type N-glycans in comparison with primary melanoma cells (WM115). To identify the glycoproteins expressing these N-glycans, glycopeptides having polyLacNAc-type N-glycans were captured by a Datura stramonium agglutinin (DSA)-immobilized agarose column. The captured glycopeptides were analyzed by LC/MS after removing N-glycans, and some glycoproteins such as basigin, lysosome-associated membrane protein-1 (LAMP-1), and chondroitin sulfate proteoglycan 4 (CSPG4) were identified in both WM115 and WM266-4 cells. The expression level of polyLacNAc of CSPG4 in WM266-4 cells was significantly higher than that in WM115 cells. In addition, sulfation patterns of chondroitin sulfate (CS) chains in CSPG4 showed dramatic changes between these cell lines. These data show that characteristic glycans attached to common proteins observed in different stages of cancer cells will be useful markers for determining degree of malignancies of tumor cells.


Asunto(s)
Amino Azúcares/química , Glicoproteínas/metabolismo , Melanoma/metabolismo , Polisacáridos/metabolismo , Secuencia de Aminoácidos , Western Blotting , Secuencia de Carbohidratos , Línea Celular Tumoral , Cromatografía de Afinidad/métodos , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Humanos , Espectrometría de Masas/métodos , Melanoma/patología , Datos de Secuencia Molecular , Metástasis de la Neoplasia , Polisacáridos/química
9.
Electrophoresis ; 34(22-23): 3198-205, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24347271

RESUMEN

We have identified novel CE conditions for the separation of 7-amino-4-methylcoumarin-labeled monosaccharides and oligosaccharides from glycoproteins. Using a neutrally coated capillary and alkaline borate buffer containing hydroxypropylcellulose and ACN, saccharide derivatives form anionic borate complexes, which move from the cathode to the anode in an electric field and are detected near the anodic end. Excess labeling reagents and other fluorescent products remain at the cathodic end. Fluorimetric detection using an LED as a light source enables determination of monosaccharide derivatives with good linearity between at least 0.4 and 400 µM, may correspond to 140 amol to 140 fmol. The lower LOD (S/N = 5) is only 80 nM in the sample solution (ca. 28 amol). The results were comparable to reported values using fluorometric detection LC. The method was also applied to the analysis of oligosaccharides that were enzymatically released from glycoproteins. Fine resolution enables profiling of glycans in glycoproteins. The applicability of the method was examined by applying it to other derivatives labeled with nonacidic tags such as ethyl p-aminobenzoate- and 2-aminoacridone-labeled saccharides.


Asunto(s)
Electroforesis Capilar/métodos , Glicoproteínas/química , Monosacáridos/análisis , Oligosacáridos/análisis , Animales , Bovinos , Pollos , Cumarinas/química , Humanos , Límite de Detección , Monosacáridos/química , Oligosacáridos/química
10.
J Chromatogr A ; 1309: 76-83, 2013 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-23958695

RESUMEN

Monoclonal antibody (mAb) pharmaceuticals are much more complex than small-molecule drugs. Such complex characteristics raise challenging questions for regulatory evaluation. Although heterogeneity in mAbs based on their charge variants has been mainly evaluated using gel-based isoelectric focusing (IEF) method, recent development in capillary electrophoresis and microchip electrophoresis has made it possible to assure their heterogeneities in more easy and rapid manner. In the present paper, we customized the imaged microchip isoelectric focusing (mIEF) for the analysis of mAbs, and compared the customized version with the conventional capillary isoelectric focusing (cIEF) method, and found that mIEF has much higher performance in operations, and its resolving powers are comparable with those obtained by cIEF.


Asunto(s)
Anticuerpos Monoclonales/química , Electroforesis por Microchip/métodos , Focalización Isoeléctrica/métodos , Preparaciones Farmacéuticas/química , Control de Calidad
11.
Glycoconj J ; 30(9): 881-8, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23959431

RESUMEN

Four types of neutral glycosphingolipids (LacCer, Gb3Cer, Gb4Cer, and IV3αGalNAc-Gb4Cer; 10 pmol each) were analyzed using high-performance liquid chromatography (HPLC)-electrospray ionization quadrupole ion trap time-of-flight (ESI-QIT-TOF) mass spectrometry (MS) with a repeated high-speed polarity and MSn switching system. This system can provide six types of mass spectra, including positive and negative ion MS, MS2, and MS3 spectra, within 1 s per cycle. Using HPLC with a normal-phase column, information on the molecular weights of major molecular species of four neutral glycosphingolipids was obtained by detecting [M+Na]+ in the positive ion mode mass spectra and [M−H]− in the negative ion mode mass spectra. Sequences of glycosphingolipid oligosaccharide were obtained in the negative ion MS2 spectra. In addition, information on the ceramide structures was clearly obtained in the negative ion MS3 mass spectra. GlcCer molecular species were analyzed by HPLC-ESI-QIT-TOF MS with a reversed-phase column using 1 pmole of GlcCer. The structures of the seven molecular species of GlcCer, namely, d18:1-C16:0, d18:1-C18:0, d18:1-C20:0, d18:1-C22:0, d18:1-C23:0, d18:1-C24:1, and d18:1-C24:0, were characterized using positive ion MS and negative ion MS, MS2, and MS3. The established HPLC-ESI-QIT-TOF MS with MSn switching and a normal phase column has been successfully applied to the structural characterization of LacCer and Gb4Cer in a crude mixture prepared from human erythrocytes.


Asunto(s)
Glicoesfingolípidos/química , Cromatografía Líquida de Alta Presión/métodos , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos
12.
Anal Chem ; 85(16): 7859-65, 2013 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-23931631

RESUMEN

High-sensitivity capillary electrophoresis-electrospray ionization quadrupole ion trap time-of-flight mass spectrometry (CE-ESI-QIT-TOF MS) was developed to structurally characterize four kinds of pyridylaminated (PA) oligosaccharides, i.e., lactose (Lac)-PA, globotriose (Gb3)-PA, globotetraose (Gb4)-PA, and IV(3) αGalNAc-Gb4 (Forssman antigen)-PA, derived from neutral glycosphingolipids. The CE-MS system included the head-column field-amplified sample stacking (HC-FASS) method for effective sample injection into a capillary column in CE, a sheathless interface between CE and a mass spectrometer, and MS and tandem MS (MS(2)) measurements with narrow mass range repeated high-speed switching. The total sensitivity of the developed CE-MS system was about 20,000 times higher than that of the conventional CE-MS system consisting of pressure injection, a sheath-flow interface, and a wide mass range measurement. The MS and MS(2) spectra of the four PA-oligosaccharides at a concentration of 25 amol/µL in mixtures (each 250 amol/10 µL in a tube) clearly showed protonated molecular ions ([M + H](+)) and the fragment ions responsible for the sequential elimination of saccharides. The developed CE-MS system is a powerful method for the structural characterization of glycosphingolipids extracted from very small amounts of biological materials and could be extended to the structural characterization of oligosaccharides derived from glycoproteins.


Asunto(s)
Electroforesis Capilar/métodos , Glicoesfingolípidos/química , Oligosacáridos/química , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masas en Tándem/métodos , Conformación de Carbohidratos , Límite de Detección
13.
Artículo en Inglés | MEDLINE | ID: mdl-23584042

RESUMEN

During the course of studies on the analysis of O-glycans in biological samples, we found that significant amount of free glycans are present in normal human serum samples. The most abundant free glycan was disialo-biantennary glycan typically observed in transferrin which is one of the abundant glycoproteins found in sera. Minor glycans were also considered to be mainly due to transferrin, but some glycans were derived from mucin-type O-glycans, although the amount was quite minute. However, high mannose-type glycans could not be detected at all. Although there have been many reports on the presence of intracellular "free" N-glycans (mainly derived from high mannose-type glycans) generated either from lipid-linked oligosaccharides or from misfolded glycoproteins through endoplasmic-reticulum associated protein degradation pathway, there is little information on the presence of free glycans in extracellular matrix and biological fluids such as serum. This report is the first one which demonstrates the presence of free glycans due to glycoproteins in sera.


Asunto(s)
Glicoproteínas/química , Polisacáridos/análisis , Polisacáridos/sangre , Secuencia de Carbohidratos , Cromatografía Líquida de Alta Presión/métodos , Glicoproteínas/sangre , Humanos , Datos de Secuencia Molecular , Espectrometría de Masa por Ionización de Electrospray/métodos , Transferrina/química
14.
Anal Chem ; 85(6): 3325-33, 2013 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-23406169

RESUMEN

A method is proposed for the analysis of O-glycans as 9-fluorenylmethyl (Fmoc) derivatives. After releasing the O-glycans from the protein backbone in the presence of ammonia-based media, the glycosylamines thus formed are conveniently labeled with Fmoc-Cl and analyzed by HPLC and MALDI-TOF MS after easy purification. Fmoc labeled O-glycans showed 3.5 times higher sensitivities than those labeled with 2-aminobenzoic acid in fluorescent detection. Various types of O-glycans having sialic acids, fucose, and/or sulfate residues were successfully labeled with Fmoc and analyzed by HPLC and MALDI-TOF MS. The method was applied to the comprehensive analysis of O-glycans expressed on MKN45 cells (human gastric adenocarcinoma). In addition, Fmoc-derivatized O-glycans were easily converted to free hemiacetal or glycosylamine-form glycans that are available for fabrication of glycan array and neoglycoproteins. To demonstrate the availability of our methods, we fabricate the glycan array with Fmoc labeled glycans derived from mucin samples and cancer cells. The model studies using the glycan array showed clear interactions between immobilized glycans and some lectins.


Asunto(s)
Fluorenos/química , Polisacáridos/análisis , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Animales , Bovinos , Línea Celular Tumoral , Cromatografía Líquida de Alta Presión/métodos , Humanos , Porcinos
15.
Anal Biochem ; 431(2): 120-6, 2012 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-22982507

RESUMEN

The oligosaccharide structure is very important in biopharmaceuticals because of its effects on protein function, including efficacy and half-life. N-glycolylneuraminic acid (Neu5Gc) and Galα1-3Gal (α-Gal) residues are known to show immunogenicity in humans. It is now understood that murine cell lines, such as NS0 or SP2, which are typically used for biopharmaceutical manufacture, produce proteins containing Neu5Gc and α-Gal residues. The expression of these specific residues is affected by the cell line and culture conditions. Therefore, monitoring and controlling the levels of these epitopes are important for the quality control of biopharmaceuticals. To detect the two epitopes on a therapeutic antibody produced by NS0 cells, we applied partial-filling capillary electrophoresis using anti-Neu5Gc antibody and α-galactosidase. In the anti-Neu5Gc antibody filling method, one minor glycan peak with Neu5Gc residues at the nonreducing end disappeared specifically from the electropherogram. In the α-galactosidase filling method, some minor peaks with α1,3-linked Gal residues disappeared. However, in a therapeutic antibody from Chinese hamster ovary cells, no peaks disappeared with the two methods. These results show this method can be used to specifically detect and quantify the two epitopes on biopharmaceuticals with high sensitivity.


Asunto(s)
Anticuerpos Monoclonales , Disacáridos , Epítopos , Ácidos Neuramínicos , Anticuerpos Monoclonales/análisis , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Línea Celular Tumoral , Disacáridos/inmunología , Disacáridos/aislamiento & purificación , Electroforesis Capilar , Epítopos/química , Epítopos/inmunología , Epítopos/aislamiento & purificación , Humanos , Ácidos Neuramínicos/inmunología , Ácidos Neuramínicos/aislamiento & purificación
16.
J Pharm Biomed Anal ; 70: 718-26, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22795310

RESUMEN

In the series of our previous reports, we showed that some cancer cell lines specifically express polylactosamine-type N-glycans and such glycans were often modified with fucose and sulfate residues. To confirm the proteins expressing these glycans, glycopeptide mixture obtained by digestion of whole protein fractions with trypsin was captured by a polylactosamine-specific lectin, Datura strasmonium agglutinin (DSA). And the peptides and glycans of the captured glycopeptides after digestion with N-glycoamidase F were extensively analyzed by HPLC and MS techniques. We found that some glycoproteins such as CD107a and CD107b commonly contained polylactosamine-type glycans in all the examined cancer cells. But integrin-α5 (CD49e) and carcinoembryonic antigen-related cell adhesion molecule 5 (CD66e) having these glycans were specifically found in U937 (human T-lymphoma) and MKN45 (human gastric cancer) cells, respectively. These data clearly indicate that specific glycans attached to specific proteins will be promising markers for specific tumors with high accuracy.


Asunto(s)
Biomarcadores de Tumor/aislamiento & purificación , Neoplasias/química , Proteoglicanos/aislamiento & purificación , Western Blotting , Cromatografía de Afinidad , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Humanos , Inmunoprecipitación , Células Jurkat , Mapeo Peptídico , Lectinas de Plantas/química , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Células U937
17.
J Chromatogr A ; 1246: 84-9, 2012 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-22410158

RESUMEN

An online preconcentration technique, large-volume sample stacking with an electroosmotic flow pump (LVSEP) was combined with partial filling affinity capillary electrophoresis (PFACE) to realize highly sensitive analysis of the interaction of glycoprotein-derived oligosaccharides with some plant lectins. Oligosaccharides derivatized with 8-aminopyrene-1,3,6-trisulfonic acid (APTS) were delivered to an entire neutrally-coated capillary and then lectin solution was hydrodynamically introduced from the outlet of the capillary as a short plug. A negative voltage was then applied after immersion of both ends of the capillary in 100 mM Tris-acetate buffer, pH 7.0 containing 0.5% hydroxypropylcellulose as electrophoresis buffers. A low concentration of electrolytes in the sample solution causes a significant flow by electroendosmosis from anode to cathode and the APTS-labeled oligosaccharides move quickly towards the anode and concentrate in the lectin phase. Finally, electroosmotic flow becomes negligible when the capillary is filled with the background electrolyte delivered from the anodic reservoir and APTS-labeled saccharides pass through the lectin plug and are detected at the anodic end. If the APTS-labeled oligosaccharides are recognized by the lectin, the migration profiles should be altered. The sensitivity was enhanced by a factor of ca. 900 compared to typical hydrodynamic injection (3.45 kPa, 10s). By this method, increased residence time of APTS-saccharides in the lectin plug indicates highly efficient interaction with lectins, which differs completely from the results obtained by ordinary lectin PFACE. The run-to-run repeatability (n=18) of the migration time and peak area was high, with relative standard deviations of less than 0.7% and 6.1%, respectively.


Asunto(s)
Electroósmosis/métodos , Electroforesis Capilar/métodos , Glicoproteínas/química , Oligosacáridos/análisis , Animales , Conformación de Carbohidratos , Secuencia de Carbohidratos , Humanos , Datos de Secuencia Molecular , Oligosacáridos/química , Oligosacáridos/metabolismo , Lectinas de Plantas/metabolismo , Pirenos/química , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Porcinos
18.
Anal Chem ; 84(5): 2373-9, 2012 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-22394092

RESUMEN

Minor N-linked glycans containing N-glycolylneuraminic acid residues and/or α-Gal epitopes (i.e., galactose-α1,3-galactose residues) have been reported to be present in recombinant monoclonal antibody (mAb) therapeutics. These contaminations are due to their production processes using nonhuman mammalian cell lines in culture media containing animal-derived materials. In case of the treatment of tumors, we inevitably use such mAbs by careful risk-benefit considerations to prolong patients' lives. However, expanding their clinical applications such as for rheumatism, asthma, and analgesia demands more careful evaluation of the product characteristics. The present work for detailed evaluations of N-glycans demonstrates the methods using capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) and a combination of high-performance liquid chromatography and electrospray ionization time-of-flight mass spectrometry. The CE-LIF method provides excellent separation of both major and minor N-glycans from six commercial mAb pharmaceuticals within 30 min and clearly indicates that a possible trigger of immunogenicity in humans due to the presence of nonhuman N-glycans is present. We strongly believe that the proposed method will be a powerful tool for the analysis of N-glycans of recombinant mAb products in various development stages, such as clone selection, process control, and routine release testing to ensure safety and efficacy of the products.


Asunto(s)
Anticuerpos Monoclonales/metabolismo , Electroforesis Capilar , Polisacáridos/análisis , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/genética , Secuencia de Carbohidratos , Cromatografía Líquida de Alta Presión , Galactosa/análisis , Glicosilación , Rayos Láser , Datos de Secuencia Molecular , Ácidos Neuramínicos/análisis , Polisacáridos/aislamiento & purificación , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
19.
Neurochem Res ; 37(6): 1315-24, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22392257

RESUMEN

The atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) is a quite convenient soft ionization for biomolecules, keeping analytes atmospheric conditions instead of high vacuum conditions. In this study, an AP-MALDI ion source has been coupled to a quadrupole ion trap time-of-flight (QIT-TOF) mass spectrometer, which is able to perform MS(n) analysis. We applied this system to the structural characterization of monosialogangliosides, GM1 (NeuAc) and GM2 (NeuAc), disialogangliosides, GD2 (NeuAc, NeuAc), GD1a (NeuAc, NeuAc) and GD1b (NeuAc, NeuAc) and trisialoganglioside GT1a (NeuAc, NeuAc, NeuAc). In this system, the negative ion mass spectra of MS, MS(2) and MS(3), a set of three mass spectra, were able to measure within 2 s per cycle. Thus, obtained results demonstrate that the negative ion mode MS, MS(2) and MS(3) spectra provided sufficient information for the determination of molecular weights, oligosaccharide sequences and ceramide structures, and indicate that the AP-MALDI-QIT-TOF mass spectrometry keeping analytes atmospheric conditions with MS(n) switching is quite useful and convenient for structural analyses of various types of sialic acid-containing GSLs, gangliosides.


Asunto(s)
Gangliósidos/química , Animales , Química Encefálica , Secuencia de Carbohidratos , Cromatografía de Gases y Espectrometría de Masas/métodos , Humanos , Datos de Secuencia Molecular , Oligosacáridos/química , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos
20.
Anal Biochem ; 421(2): 595-606, 2012 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-22212498

RESUMEN

We developed an automated apparatus for rapid releasing of O-glycans from mucin-type glycoproteins [Anal. Biochem. 371 (2007) 52-61; Anal. Chem. 82 (2010) 7436-7443] and applied the device to analyze them in some cancer cell lines [J. Proteome Res. 8 (2009) 521-537]. We also found that the device is useful to release glycosaminoglycans from proteoglycans [Anal. Biochem. 362 (2007) 245-251]. Based on these studies, we developed a method for one-pot analysis of mucin-type glycans and glycosaminoglycans after releasing them from total protein pool obtained from some cancer cell lines. Mucin-type glycans were analyzed by a combination of high-performance liquid chromatography and mass spectrometry techniques, and glycosaminoglycans were analyzed by capillary electrophoresis as fluorescent-labeled unsaturated disaccharides after digestion with specific eliminases followed by fluorescent labeling. Ten cancer cell lines, including blood cancer cells as well as epithelial cancer cells, were used to assess the method. The results clearly revealed that both mucin-type glycans and glycosaminoglycans showed quite interesting profiles. Thus, the current technique will be a powerful tool for discovery of glycan markers of diseases.


Asunto(s)
Biomarcadores de Tumor/análisis , Glicosaminoglicanos/análisis , Neoplasias/química , Polisacáridos/análisis , Línea Celular Tumoral , Cromatografía de Afinidad , Cromatografía Líquida de Alta Presión , Electroforesis Capilar , Humanos , Neoplasias/patología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectrometría de Masas en Tándem
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