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1.
Foods ; 9(6)2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32531942

RESUMO

The application of ß-carotene in food industry is limited due to its chemical instability. The drawback may be overcome by designing new delivery systems. The stability of ß-carotene complexed with chitooligosaccharides by kneading, freeze-drying and sonication methods was investigated under various conditions. The first-order kinetics parameters of the reaction of ß-carotene degradation were calculated. The complexation improved the stability of ß-carotene at high temperatures and ensured its long-term stability in the dark at 4 °C and 24 °C, and in the light at 24 °C. In water solutions, the best characteristics were exhibited by the complexes prepared by freeze-drying and sonication methods. In the powder form, the complexes retained their colour for the period of the investigation of four months. The calculated total colour differences of the complexes were qualified as appreciable, detectable by ordinary people, but not large. Therefore, ß-carotene-chitooligosaccharides complexes could be used as a new delivery system suitable for food fortification.

2.
Carbohydr Polym ; 225: 115226, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31521299

RESUMO

ß-carotene and chitooligosaccharides are bioactive compounds that find their application in the food industry as well in biomedical fields. However, the application of ß-carotene is limited due to its very low water solubility, as well as its air, light and temperature sensitivity. The preparation of ß-carotene-chitooligosaccharides complexes by mechanochemical methods was presented. Their physical and chemical properties including solubility, size, zeta potential and radical scavenging activity were investigated. The interaction of the two components was shown by NMR, FT-IR, and Raman spectroscopy. The complexes were analysed by scanning and transmission electron microscopy. Chitooligosaccharides could serve as a carrier for ß-carotene delivery. The complexation did not cause the loss of the radical scavenging activity of ß-carotene and guaranteed its water solubility.


Assuntos
Quitina/análogos & derivados , Substâncias Macromoleculares , beta Caroteno , Antioxidantes/química , Quitina/química , Quitina/isolamento & purificação , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Solubilidade , Temperatura , Água/química , beta Caroteno/química , beta Caroteno/isolamento & purificação
4.
Colloids Surf B Biointerfaces ; 169: 126-134, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29758538

RESUMO

Nisin is a known bacteriocin approved as a food additive for food preservation. It exhibits a wide spectrum antimicrobial activity against Gram-positive bacteria. Iron oxide magnetic nanoparticles were synthesized and characterized by X-ray diffraction method. A main part of iron oxide nanoparticles was found to be maghemite though a small quantity of magnetite could also be present. Magnetic nanoparticles were stabilized by citric, ascorbic, gallic or glucuronic acid coating. Stable iron oxide magnetic nanoparticles were functionalized by nisin using a simple and low cost adsorption method. Nisin loading was confirmed by FT-IR spectra, thermogravimetric analysis, dynamic light scattering and atomic force microscopy methods. Nisin-loaded iron oxide magnetic nanoparticles were stable at least six weeks as judged by the measurements of zeta-potential and hydrodynamic diameter. The antimicrobial activity of nisin-loaded iron oxide magnetic nanoparticles was demonstrated toward Gram-positive bacteria. Functionalized nanoparticles could therefore find the application as antimicrobials in innovative and emerging technologies based on the magnetic field.


Assuntos
Antibacterianos/farmacologia , Compostos Férricos/farmacologia , Bactérias Gram-Positivas/efeitos dos fármacos , Nanopartículas de Magnetita/química , Nisina/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Compostos Férricos/química , Bactérias Gram-Positivas/citologia , Campos Magnéticos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Nisina/química , Tamanho da Partícula , Propriedades de Superfície
5.
Aging (Albany NY) ; 10(5): 868-901, 2018 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-29779015

RESUMO

Non-enzymatic protein modifications occur inevitably in all living systems. Products of such modifications accumulate during aging of cells and organisms and may contribute to their age-related functional deterioration. This review presents the formation of irreversible protein modifications such as carbonylation, nitration and chlorination, modifications by 4-hydroxynonenal, removal of modified proteins and accumulation of these protein modifications during aging of humans and model organisms, and their enhanced accumulation in age-related brain diseases.


Assuntos
Envelhecimento/metabolismo , Encefalopatias/metabolismo , Encefalopatias/fisiopatologia , Estresse Oxidativo/fisiologia , Processamento de Proteína Pós-Traducional/fisiologia , Animais , Halogenação/fisiologia , Humanos , Carbonilação Proteica/fisiologia
6.
Front Microbiol ; 9: 3006, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30619116

RESUMO

Nisin is a recognized bacteriocin widely used in food processing, however, being ineffective against gram-negative bacteria and in complex food systems. As a result, the research of methods that have cell wall-permeabilizing activity is required. In this study, electroporation to trigger sensitization of gram-negative bacteria to nisin-loaded pectin nanoparticles was used. As a model microorganism, bioluminescent strain of E. coli was introduced. Inactivation kinetics using nanosecond pulsed electric fields (PEFs) and nisin nanoparticles have been studied in a broad range (100-900 ns, 10-30 kV/cm) of pulse parameters. As a reference, the microsecond range protocols (100 µs × 8) have been applied. It was determined that the 20-30 kV/cm electric field with pulse duration ranging from 500 to 900 ns was sufficient to cause significant permeabilization of E. coli to trigger a synergistic response with the nisin treatment. The kinetics of the inactivation was studied with a time resolution of 2.5 min, which provided experimental evidence that the efficacy of nisin-based treatment can be effectively controlled in time using PEF. The results and the proposed methodology for rapid detection of bacteria inactivation rate based on bioluminescence may be useful in the development and optimization of protocols for PEF-based treatments.

7.
Front Microbiol ; 8: 2678, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29375537

RESUMO

Nisin is a known bacteriocin, which exhibits a wide spectrum of antimicrobial activity, while commonly being inefficient against Gram-negative bacteria. In this work, we present a proof of concept of novel antimicrobial methodology using targeted magnetic nisin-loaded nano-carriers [iron oxide nanoparticles (NPs) (11-13 nm) capped with citric, ascorbic, and gallic acids], which are activated by high pulsed electric and electromagnetic fields allowing to overcome the nisin-resistance of bacteria. As a cell model the Gram-positive bacteria Bacillus subtilis and Gram-negative Escherichia coli were used. We have applied 10 and 30 kV cm-1 electric field pulses (100 µs × 8) separately and in combination with two pulsed magnetic field protocols: (1) high dB/dt 3.3 T × 50 and (2) 10 mT, 100 kHz, 2 min protocol to induce additional permeabilization and local magnetic hyperthermia. We have shown that the high dB/dt pulsed magnetic fields increase the antimicrobial efficiency of nisin NPs similar to electroporation or magnetic hyperthermia methods and a synergistic treatment is also possible. The results of our work are promising for the development of new methods for treatment of the drug-resistant foodborne pathogens to minimize the risks of invasive infections.

8.
Biotechnol Prog ; 33(1): 245-251, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27792287

RESUMO

The relationship between pectin structure and the antimicrobial activity of nisin-loaded pectin particles was examined. The antimicrobial activity of five different nisin-loaded pectin particles, i.e., nisin-loaded high methoxyl pectin, low methoxyl pectin, pectic acid, dodecyl pectin with 5.4 and 25% degree of substitution were tested in the pH range of 4.0-7.0 by agar-diffusion assay and agar plate count methods. It was found that the degree of esterification of carboxyl group of galacturonic acid in pectin molecule is important for the antimicrobial activity of nisin-loaded pectin particles. Nisin-loaded particles prepared using pectic acid or the pectin with low degree of esterification exhibit higher antimicrobial activity than nisin-loaded high methoxyl pectin particles. Pectins with free carboxyl groups or of low degree of esterification are the most suitable for particles preparation. Moreover, nisin-loaded pectin particles were active at close to neutral or neutral pH values. Therefore, they could be effectively applied for food preservation. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:245-251, 2017.


Assuntos
Anti-Infecciosos/química , Conservação de Alimentos , Nisina/química , Pectinas/química , Anti-Infecciosos/farmacologia , Arthrobacter/efeitos dos fármacos , Arthrobacter/patogenicidade , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/patogenicidade , Esterificação , Concentração de Íons de Hidrogênio , Nisina/farmacologia , Pectinas/farmacologia
9.
Biotechnol Prog ; 31(3): 808-14, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25832546

RESUMO

The influence of l-homoarginine on the heat-induced aggregation of three model proteins, i.e. porcine, mink, and human growth hormones was investigated by circular dichroism spectroscopy. It was found that the effect of l-homoarginine as an analogue of arginine depends on the concentration of the additive as well as the protein itself. l-Homoarginine increased the onset temperature of heat-induced aggregation of both porcine and mink growth hormones. However, the formation of human growth hormone aggregates was increased at low concentrations of l-homoarginine. Only at higher concentrations of the additive was the onset temperature of human growth hormone aggregation found to increase. Additional experiments of human growth hormone melting in the presence of histidine, lysine, and sodium chloride were performed. The effect of lysine was similar as in the presence of l-homoarginine. It follows that in protein formulations low concentrations of amino acids should be used with some precaution. At low concentration of additive, depending on the charge of both protein and amino acid used, the promotion of aggregation of unfolding intermediates may occur.


Assuntos
Arginina/química , Hormônio do Crescimento/química , Homoarginina/química , Hormônio do Crescimento Humano/química , Animais , Arginina/análogos & derivados , Dicroísmo Circular , Histidina/química , Temperatura Alta , Humanos , Lisina/química , Vison , Cloreto de Sódio/química , Suínos
10.
Mol Biotechnol ; 56(7): 644-52, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24532228

RESUMO

Saccharomyces cerevisiae K2 toxin is a highly active extracellular protein, important as a biocontrol agent for biotechnological applications in the wine industry. This protein is produced at negligible levels in yeast, making difficult to isolate it in amounts sufficient for investigation and generation of analysis tools. In this work, we demonstrate the use of a bacterial system for expression of the recombinant K2 protein, suitable for generation of antibodies specific for toxin of the yeast origin. Synthesis of the full-length S. cerevisiae K2 preprotoxin in Escherichia coli was found to be toxic to the host cell, resulting in diminished growth. Such effect was abolished by the introduction of the C-terminal truncation into K2 protein, directing it into non-toxic inclusion body fraction. The obtained protein is of limited solubility thus, facilitating the purification by simple and efficient chromatography-free procedure. The protein aggregates were successfully refolded into a soluble form yielding sufficient amounts of a tag-less truncated K2 protein suitable for polyclonal antibody production. Antibodies were raised in rabbit and found to be specific for detection of both antigen and native S. cerevisiae K2 toxin.


Assuntos
Fatores Matadores de Levedura/biossíntese , Fatores Matadores de Levedura/genética , Saccharomyces cerevisiae/genética , Sequência de Aminoácidos , Animais , Anticorpos/imunologia , Clonagem Molecular , Escherichia coli/genética , Regulação Fúngica da Expressão Gênica , Fatores Matadores de Levedura/imunologia , Fatores Matadores de Levedura/isolamento & purificação , Coelhos
11.
J Mol Microbiol Biotechnol ; 23(3): 219-26, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23594427

RESUMO

The influence of osmotic shock in the presence of exogenous osmolytes on the formation and composition of insoluble protein fraction in Escherichia coli was investigated. Interferon-α5 (IFN-α5) expressed in E. coli BL21(DE3) was used as a model protein. Cells were cultivated at three different temperatures of 25, 30, and 37°C. Two different osmolytes were used. Glycine as an amino acid metabolized by E. coli, or betaine which is not metabolized by cells, was added to the growth medium in the presence of salt. In both cases (i.e. when metabolized or non-metabolized amino acid was used), IFN-α5 formed the aggregates, except at 25°C of cultivation. Moreover, the differences in the quantitative composition of insoluble protein fraction were revealed by the proteomic analysis. The amount of some identified proteins increased, decreased, or did not change in the samples cultivated under osmotic shock in the presence of betaine as compared with the sample cultivated without salt and betaine in growth medium.


Assuntos
Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Pressão Osmótica/fisiologia , Betaína/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Interferon-alfa/genética , Interferon-alfa/metabolismo , Sais/farmacologia , Temperatura
12.
Free Radic Res ; 47 Suppl 1: 93-137, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23560617

RESUMO

The advanced glycoxidation end products (AGEs) and lipoxidation end products (ALEs) contribute to the development of diabetic complications and of other pathologies. The review discusses the possibilities of counteracting the formation and stimulating the degradation of these species by pharmaceuticals and natural compounds. The review discusses inhibitors of ALE and AGE formation, cross-link breakers, ALE/AGE elimination by enzymes and proteolytic systems, receptors for advanced glycation end products (RAGEs) and blockade of the ligand-RAGE axis.


Assuntos
Antioxidantes/metabolismo , Diabetes Mellitus/tratamento farmacológico , Produtos Finais de Glicação Avançada/metabolismo , Peroxidação de Lipídeos , Antioxidantes/farmacologia , Reagentes para Ligações Cruzadas/metabolismo , Reagentes para Ligações Cruzadas/farmacologia , Complicações do Diabetes/metabolismo , Diabetes Mellitus/metabolismo , Diabetes Mellitus/fisiopatologia , Produtos Finais de Glicação Avançada/antagonistas & inibidores , Humanos , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise/efeitos dos fármacos , Receptor para Produtos Finais de Glicação Avançada/metabolismo
13.
Biotechnol Appl Biochem ; 58(4): 277-84, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21838803

RESUMO

Five compounds of different chemical structure were tested for aggregation suppression during the refolding of porcine and mink growth hormones as model proteins from Escherichia coli inclusion bodies by the dilution method. Of all compounds tested in this work, 3-guanidinopropionic acid (GPA) containing a guanidinium group was the most effective additive for aggregation suppression. Anti-aggregatory properties of GPA were compared with the ones of l-arginine.


Assuntos
Escherichia coli/metabolismo , Guanidinas/química , Corpos de Inclusão/química , Propionatos/química , Redobramento de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Animais , Arginina/química , Escherichia coli/química , Hormônio do Crescimento/biossíntese , Hormônio do Crescimento/química , Hormônio do Crescimento/isolamento & purificação , Corpos de Inclusão/metabolismo , Vison , Proteínas Recombinantes/biossíntese , Suínos
14.
Biologicals ; 39(3): 181-8, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21550265

RESUMO

Circular dichroism spectroscopy was used to study the effect of l-arginine on the temperature related unfolding and aggregation of three growth hormones, i.e. human, porcine and mink growth hormones, and human interferon-α2b. (L)-arginine can stabilize some proteins and suppress their aggregation as it was exemplified by porcine and mink growth hormones. For some other proteins, on the contrary, the effect of arginine can be negative. Even at low concentrations the amino acid is able to promote the aggregation as it was demonstrated by the experiments with human growth hormone and interferon-α2b. (L)-arginine seems not to be a universal excipient for preventing the temperature related aggregation of proteins in contrast to its widespread application in the refolding process.


Assuntos
Arginina/farmacologia , Multimerização Proteica/efeitos dos fármacos , Resposta a Proteínas não Dobradas/efeitos dos fármacos , Animais , Dicroísmo Circular , Hormônio do Crescimento/química , Hormônio do Crescimento/efeitos dos fármacos , Temperatura Alta , Hormônio do Crescimento Humano/química , Hormônio do Crescimento Humano/efeitos dos fármacos , Humanos , Técnicas In Vitro , Interferon alfa-2 , Interferon-alfa/química , Interferon-alfa/efeitos dos fármacos , Vison , Nefelometria e Turbidimetria , Dobramento de Proteína/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína/efeitos dos fármacos , Proteínas Recombinantes , Suínos
15.
Mol Biotechnol ; 49(1): 11-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21207196

RESUMO

The influence of L-arginine on the temperature-induced aggregation of porcine and mink growth hormones was studied by fluorescence spectroscopy. It was found that L-arginine suppresses the heat-induced aggregation. Moreover, the analysis of L-arginine interaction with the native proteins by fluorescence spectroscopy and circular dichroism spectroscopy revealed no significant changes in their native structure. On the basis of the results, L-arginine could be considered as a potential additive for the prevention of storage and temperature-related denaturation and aggregation of veterinary growth hormones.


Assuntos
Arginina/química , Hormônio do Crescimento/química , Desnaturação Proteica , Animais , Dicroísmo Circular/métodos , Temperatura Alta , Vison , Estrutura Terciária de Proteína , Espectrometria de Fluorescência , Suínos
16.
Biochimie ; 91(9): 1123-30, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19524011

RESUMO

In this study the bioactivity of three differently glycosylated blood coagulation factor VII (FVII) variants (human plasma FVII, recombinant human FVII produced in CHO and BHK cell cultures) were analyzed and compared. Surface plasmon resonance studies of FVII interaction with soluble and full length TF together with FVII autoactivation assays revealed that BHK-derived FVII has the highest bioactivity, while human plasma and CHO-derived FVII showed very similar bioactivity. The affinity of FVII variants to TF correlates with FVII autoactivation rates--the higher the affinity, the faster the autoactivation rate.


Assuntos
Fator VII/metabolismo , Proteínas Recombinantes/metabolismo , Animais , Células CHO , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Cricetinae , Cricetulus , Fator VII/genética , Glicosilação , Humanos , Cinética , Ligação Proteica , Proteínas Recombinantes/genética , Ressonância de Plasmônio de Superfície , Tromboplastina/metabolismo
17.
Int J Biol Macromol ; 44(5): 428-34, 2009 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-19428477

RESUMO

Cyclodextrins with different ring size and ring substituents were tested for recombinant mink and porcine growth hormones aggregation suppression in the refolding process from Escherichia coli inclusion bodies. Methyl-beta-cyclodextrin and 2-hydroxypropyl-beta-cyclodextrin show a positive effect on the aggregation suppression of both proteins. The influence of different methyl-beta-cyclodextrin and 2-hydroxypropyl-beta-cyclodextrin concentrations on the renaturation yield of both growth hormones was investigated. Moreover, methyl-beta-cyclodextrin and 2-hydroxypropyl-beta-cyclodextrin suppress not only folding-related, but also temperature-related aggregates formation of both proteins. Circular dichroism experiments (monitoring of protein solution turbidity by registering high tension voltage) showed that the onset temperature of aggregation of both growth hormones increased with increasing 2-hydroxypropyl-beta-cyclodextrin concentration. In conclusion, cyclodextrins have perspectives in biotechnology of veterinary growth hormones not only for protein production, but also for its storage.


Assuntos
Ciclodextrinas/farmacologia , Escherichia coli/genética , Hormônio do Crescimento/química , Hormônio do Crescimento/metabolismo , Corpos de Inclusão/metabolismo , Renaturação Proteica/efeitos dos fármacos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Ciclodextrinas/química , Relação Dose-Resposta a Droga , Escherichia coli/citologia , Hormônio do Crescimento/genética , Corpos de Inclusão/química , Vison , Ligação Proteica/efeitos dos fármacos , Dobramento de Proteína/efeitos dos fármacos , Proteínas Recombinantes/genética , Solubilidade , Suínos , Temperatura
18.
Biophys J ; 95(7): 3222-31, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18599640

RESUMO

Equilibrium binding ligands usually increase protein thermal stability by an amount proportional to the concentration and affinity of the ligand. High-throughput screening for the discovery of drug-like compounds uses an assay based on thermal stabilization. The mathematical description of this stabilization is well developed, and the method is widely applicable to the characterization of ligand-protein binding equilibrium. However, numerous cases have been experimentally observed where equilibrium binding ligands destabilize proteins, i.e., diminish protein melting temperature by an amount proportional to the concentration and affinity of the ligand. Here, we present a thermodynamic model that describes ligand binding to the native and unfolded (denatured) protein states explaining the combined stabilization and destabilization effects. The model also explains nonsaturation and saturation effects on the protein melting temperature when the ligand concentration significantly exceeds the protein concentration. Several examples of the applicability of the model are presented, including specific sulfonamide binding to recombinant hCAII, peptide and ANS binding to the Polo-box domain of Plk1, and zinc ion binding to the recombinant porcine growth hormone. The same ligands may stabilize and destabilize different proteins, and the same proteins may be stabilized and destabilized by different ligands.


Assuntos
Modelos Moleculares , Proteínas/química , Proteínas/metabolismo , Temperatura , Animais , Anidrases Carbônicas/metabolismo , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Relação Dose-Resposta a Droga , Hormônio do Crescimento/metabolismo , Temperatura Alta , Humanos , Ligantes , Ligação Proteica , Desnaturação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas/metabolismo , Teoria Quântica , Suínos/metabolismo , Termodinâmica , Temperatura de Transição/efeitos dos fármacos , Zinco/metabolismo , Zinco/farmacologia
19.
Biomed Chromatogr ; 22(9): 1001-7, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18506902

RESUMO

The formation of the complexes between Cibacron blue F3G-A and two therapeutic proteins, recombinant human interferon-alpha2b and recombinant human growth hormone, was investigated. The method of time-resolved limited proteolysis coupled with MALDI-TOF mass spectrometry was used. The analysis of peptide maps revealed that A(17)HR(19) and L(20)HQLAFDTYQEFEEAYIPK(38) of hGH, and R(14)TLMLLAQMR(23) and D(33)RHDFGFPQEEFGNQFQK(50) of hIFN-alpha2b, exhibit affinity to Cibacron blue F3G-A.


Assuntos
Corantes/química , Hormônio do Crescimento Humano/química , Interferon-alfa/química , Peptídeos/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Triazinas/química , Interações Medicamentosas , Humanos , Interferon alfa-2 , Ligantes , Proteínas Recombinantes
20.
Protein J ; 27(3): 170-80, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18080174

RESUMO

Fourier-transform infrared spectroscopy, in vitro bioassay and enzyme-linked immunoassay were used to study the structural-functional relationships of recombinant mink growth hormone (mGH), refolded and stored under different conditions. Porcine GH (pGH) was synthesized and used as an example. These two hormones, when refolded and stored the same way, had the same secondary structures, biological and immunological efficacy, and biological potency. Only the immunological potency differed, mGH being significantly less potent than pGH. Renaturation pH and storing frozen or at 4 degrees C in 5% glycerol did not affect either the secondary structure or the activity. However, freeze-drying raised the content of buried alpha-helices and lowered that of solvated alpha-helices and of unordered structures. These conformational changes were associated with a reduction of immunological and biological potency of mGH and of immunological potency of pGH. These findings provide original information on the secondary structure of mGH, and show that conformational changes induced by lyophilization adversely affect its activity.


Assuntos
Hormônio do Crescimento/química , Hormônio do Crescimento/imunologia , Vison/imunologia , Renaturação Proteica , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Liofilização , Hormônio do Crescimento/genética , Camundongos , Vison/genética , Dados de Sequência Molecular , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Alinhamento de Sequência , Espectroscopia de Infravermelho com Transformada de Fourier , Relação Estrutura-Atividade , Suínos , Temperatura
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