ABSTRACT
Serum amyloid A low-density lipoprotein (SAA-LDL) is formed by an oxidative interaction and is considered to be a new marker related to oxidative modification of LDL. As the effect of smoking on oxidized LDL is of concern, this study investigated the association between SAA-LDL and smoking status. A total of 578 Japanese obese outpatients (mean ± SD age 50.5 ± 14.3 years) were studied. Smoking status was examined via a self-reported questionnaire. Cardio metabolic variables, including high-sensitivity Creactive protein (hsCRP), were analysed in addition to SAA-LDL. There was an increasing trend in SAA-LDL levels from non- to ex- to current smokers, and significantly higher SAA-LDL levels were observed in current smokers versus non-smokers (median SAA-LDL level 36 µg/ml versus 28 µg/ml, respectively). This significant difference was reduced after adjusting for multiple confounders, including lipid levels. Smoking may be associated with increased levels of SAA-LDL in an obese Japanese population, but further studies are needed.
Subject(s)
Lipoproteins, LDL/blood , Obesity/blood , Serum Amyloid A Protein/analogs & derivatives , Smoking/blood , Adult , Aged , Biomarkers/blood , Blood Glucose , Blood Pressure , C-Reactive Protein/metabolism , Cholesterol/blood , Cross-Sectional Studies , Female , Humans , Japan , Male , Middle Aged , Oxidation-Reduction , Surveys and QuestionnairesABSTRACT
BACKGROUND: NC/Nga mice are known to show a spontaneous outbreak of atopic-like dermatitis accompanied by a marked elevation in serum IgE levels when reared in a conventional environment. The specific effects of such a strong serum IgE response on the development of the dermatitis and specific antigens recognized by the IgE antibodies are still uncertain. OBJECTIVE AND METHODS: To characterize the IgE of NC/Nga mice, we established IgE-secreting hybridoma clones from spleen cells of NC/Nga mice spontaneously developing dermatitis and identified variable-region genes and specific antigens of the IgE monoclonal antibodies (mAbs). Serum polyclonal IgE, as well as IgG1 and IgG2a, specific for the identified antigen were also analysed. RESULTS: Four IgE-producing hybridoma clones were established. Variable-region nucleotide sequences of the IgE mAbs showed that these clones did not necessarily share common germline gene segments (V, D or J) for each variable region, and several somatic mutations had occurred in the V gene segments. Through antigen screening, histone H3 was identified to be an auto-antigen recognized by three of the four IgE mAbs. Serum IgE as well as IgG1 specific for histone H3 were almost undetectable in 6-week-old mice, but rapidly increased by 10-12 weeks of age. This age-dependent increase in the serum anti-histone H3 IgE was roughly in parallel with the onset of dermatitis, and slightly preceding total IgE elevation. The serum-specific IgE level correlated well with a dermatitis-severity score of each mouse at 12-16 weeks of age, and weakly with the severity of ear erosion of each mouse over 28 weeks of age. Furthermore, immunologically detectable histone-H3 antigens were observed in skin tissue sections from the dermatitis sites. CONCLUSION: In NC/Nga mice, anti-histone H3 auto-antibodies may contribute, at least in part, to the considerably elevated serum IgE and might play some roles in the development and exacerbation of dermatitis.
Subject(s)
Antibodies, Monoclonal/immunology , Autoantibodies/immunology , Autoantigens/immunology , Dermatitis, Atopic/immunology , Histones/immunology , Immunoglobulin E/blood , Age Factors , Animals , Autoantibodies/blood , Dermatitis, Atopic/pathology , Disease Models, Animal , Female , Hybridomas , Mice , Mice, Inbred Strains , Skin/immunology , Skin/pathologyABSTRACT
BACKGROUND: Effective therapy for gastro-oesophageal reflux disease (GERD) is associated with improvement in health-related quality of life. It remains unclear whether Helicobacter pylori infection protects against GERD. AIM: We evaluated the relationship between GERD and H. pylori, and whether the health-related quality of life score improved after medical treatment. METHODS: We enrolled 151 outpatients with upper abdominal symptoms; 81 patients received omeprazole 20 mg/day for 2 weeks. Health-related quality of life was assessed using the Gastrointestinal Symptom Rating Scale (GSRS) and the Psychological General Well-Being (PGWB) index. H. pylori infection was diagnosed by serum antibody or endoscopy and the relationship between GERD and H. pylori was evaluated. RESULTS: In GERD patients, the mean GSRS score improved from 2.20 to 1.67 following treatment (P < 0.01). The mean GSRS reflux symptom score improved from 2.96 to 1.67 (P < 0.01). The mean PGWB score improved from 96.36 to 107.34 (P < 0.01). All scores in GERD patients significantly improved compared with non-GERD patients. The H. pylori-positive ratio was 66.15% in GERD patients and 65.21% in non-GERD patients (P = 0.94). CONCLUSIONS: Health-related quality of life is useful for evaluation of proton pump inhibitor treatment in GERD. The presence of H. pylori was not associated with the prevalence of GERD.
Subject(s)
Anti-Ulcer Agents/therapeutic use , Gastroesophageal Reflux/drug therapy , Helicobacter Infections/drug therapy , Helicobacter pylori , Omeprazole/therapeutic use , Proton Pump Inhibitors , Female , Gastroesophageal Reflux/microbiology , Helicobacter Infections/complications , Humans , Male , Middle Aged , Quality of Life , Surveys and Questionnaires , Treatment OutcomeABSTRACT
The catalytic reaction of copper/topa quinone (TPQ) containing amine oxidase consists of the initial, well-characterized, reductive half-reaction and the following, less studied, oxidative half-reaction. We have analyzed the oxidative half-reaction catalyzed by phenylethylamine oxidase from Arthrobacter globiformis (AGAO) by rapid-scan stopped-flow measurements. Upon addition of dioxygen to the substrate-reduced AGAO at pH 8.2, the absorption bands derived from the semiquinone (TPQ(sq)) and aminoresorcinol forms of the TPQ cofactor disappeared within the dead time (<1 ms) of the measurements, indicating that the reaction of the substrate-reduced enzyme with dioxygen is very rapid. Concomitantly, an early intermediate exhibiting an absorption band at about 410 nm was formed, which then decayed with a rate constant of 390 +/- 50 s(-1). This intermediate was detected more prominently in the reaction in D2O buffer (pD 8.1) and was assigned to a Cu(II)-peroxy species. The assignment was based on the observation that addition of H2O2 to the substrate-reduced AGAO under anaerobic conditions led to the formation of a new band at about 415 nm, accompanied by partial quenching of absorption bands derived from TPQ(sq). Other intermediates exhibiting absorption bands at about 310 and 340 nm were also observed in the oxidative half-reaction. Kinetics of the disappearance of these latter bands did not correspond with that of the Cu(II)-peroxy band at 410 nm but did well with that of the increase of the 480 nm absorption band due to the reoxidized TPQ. Rapid increase of the absorption in the 320-370 nm region was also observed for the reaction of the substrate-reduced, Ni-substituted enzyme with dioxygen. On the basis of these results, a possible mechanism is proposed for the oxidative half-reaction of the bacterial copper amine oxidase.
Subject(s)
Amine Oxidase (Copper-Containing)/chemistry , Copper/chemistry , Dihydroxyphenylalanine/analogs & derivatives , Dihydroxyphenylalanine/chemistry , Amine Oxidase (Copper-Containing)/metabolism , Catalysis , Copper/metabolism , Dihydroxyphenylalanine/metabolism , Micrococcaceae/enzymology , Nickel/chemistry , Nickel/metabolism , Oxidation-Reduction , Oxygen/chemistry , Oxygen/metabolism , Peroxides/chemistry , Peroxides/metabolism , Spectrophotometry, Ultraviolet , Substrate SpecificityABSTRACT
The crystal structure of the heterotrimeric quinohemoprotein amine dehydrogenase from Paracoccus denitrificans has been determined at 2.05-A resolution. Within an 82-residue subunit is contained an unusual redox cofactor, cysteine tryptophylquinone (CTQ), consisting of an orthoquinone-modified tryptophan side chain covalently linked to a nearby cysteine side chain. The subunit is surrounded on three sides by a 489-residue, four-domain subunit that includes a diheme cytochrome c. Both subunits sit on the surface of a third subunit, a 337-residue seven-bladed beta-propeller that forms part of the enzyme active site. The small catalytic subunit is internally crosslinked by three highly unusual covalent cysteine to aspartic or glutamic acid thioether linkages in addition to the cofactor crossbridge. The catalytic function of the enzyme as well as the biosynthesis of the unusual catalytic subunit is discussed.
Subject(s)
Oxidoreductases Acting on CH-NH Group Donors/chemistry , Paracoccus denitrificans/enzymology , Amino Acid Sequence , Catalytic Domain , Coenzymes/biosynthesis , Coenzymes/chemistry , Cross-Linking Reagents , Crystallography, X-Ray , Models, Molecular , Molecular Sequence Data , Molecular Structure , Oxidation-Reduction , Oxidoreductases Acting on CH-NH Group Donors/biosynthesis , Oxidoreductases Acting on CH-NH Group Donors/genetics , Paracoccus denitrificans/genetics , Protein Structure, Quaternary , Protein Subunits , Sequence Homology, Amino AcidABSTRACT
Pseudomonas putida contains an amine dehydrogenase that is called a quinohemoprotein as it contains a quinone and two hemes c as redox active groups. Amino acid sequence analysis of the smallest (8.5 kDa), quinone-cofactor-bearing subunit of this heterotrimeric enzyme encountered difficulties in the interpretation of the results at several sites of the polypeptide chain. As this suggested posttranslational modifications of the subunit, the structural genes for this enzyme were determined and mass spectrometric de novo sequencing was applied to several peptides obtained by chemical or enzymatic cleavage. In agreement with the interpretation of the X-ray electronic densities in the diffraction data for the holoenzyme, our results show that the polypeptide of the small subunit contains four intrachain cross-linkages in which the sulfur atom of a cysteine residue is involved. Two of these cross-linkages occur with the beta-carbon atom of an aspartic acid, one with the gamma-carbon atom of a glutamic acid and the fourth with a tryptophanquinone residue, this adduct constituting the enzyme's quinone cofactor, CTQ. The thioether type bond in all four of these adducts has never been found in other proteins. CTQ is a novel cofactor in the series of the recently discovered quinone cofactors.
Subject(s)
Cysteine/chemistry , Indolequinones , Oxidoreductases Acting on CH-NH Group Donors/chemistry , Pseudomonas putida/enzymology , Sulfides/chemistry , Tryptophan/analogs & derivatives , Amino Acid Sequence , Amino Acids/chemistry , Cloning, Molecular , Cross-Linking Reagents/pharmacology , Glutamic Acid/chemistry , Heme/chemistry , Mass Spectrometry , Models, Chemical , Models, Genetic , Molecular Sequence Data , Open Reading Frames , Oxidation-Reduction , Oxidoreductases Acting on CH-NH Group Donors/genetics , Oxidoreductases Acting on CH-NH Group Donors/metabolism , Peptides/chemistry , Protein Binding , Protein Processing, Post-Translational , Quinones/chemistry , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Spectrometry, Mass, Electrospray Ionization , Tryptophan/chemistry , X-RaysABSTRACT
We looked at regional cerebellar blood flow in patients with Minamata disease (MD) using technetium-99m ethyl cysteinate dimer (99m-Tc-ECD). We carried out single-photon emission computed tomography (SPECT) on 15 patients with MD (eight men, seven women, aged 51-78 years, mean 70.5 years) and 11 control subjects (eight men, three women, aged 62-80 years, mean 72.5 years). Regional blood flow was measured in the superior, middle, and inferior portions of the cerebellar hemispheres, and the frontal, temporal and occipital cerebral lobes. The degree of cerebellar atrophy was assessed on MRI. There were significant differences in regional blood flow in all parts of the cerebellum between patients and control, but no significant decrease was observed in the cerebrum. Blood flow was lower in the inferior cerebellum than in the other parts. Even in patients without cerebellar atrophy, flow was significantly decreased regional blood flow in the inferior part.
Subject(s)
Cerebellum/blood supply , Cysteine , Mercury Poisoning, Nervous System/physiopathology , Organotechnetium Compounds , Radiopharmaceuticals , Tomography, Emission-Computed, Single-Photon , Aged , Atrophy , Cerebellum/pathology , Cerebral Cortex/blood supply , Cerebrovascular Circulation , Cysteine/analogs & derivatives , Female , Humans , Magnetic Resonance Imaging , Male , Mercury Poisoning, Nervous System/diagnostic imaging , Mercury Poisoning, Nervous System/pathology , Middle AgedABSTRACT
X-ray telescopes (XRT's) of nested thin foil mirrors are developed for Astro-E, the fifth Japanese x-ray astronomy satellite. Although the launch was not successful, the design concept, fabrication, and alignment procedure are summarized. The main purpose of the Astro-E XRT is to collect hard x rays up to 10 keV with high efficiency and to provide medium spatial resolution in limited weight and volume. Compared with the previous mission, Advanced Satellite for Cosmology and Astrophysics (ASCA), a slightly longer focal length of 4.5-4.75 m and a larger diameter of 40 cm yields an effective area of 1750 cm2 at 8 keV with five telescopes. The image quality is also improved to 2-arc min half-power diameter by introduction of a replication process. Platinum is used instead of gold for the reflectors of one of the five telescopes to enhance the high-energy response. The fabrication and alignment procedure is also summarized. Several methods for improvement are suggested for the reflight Astro-E II mission and for other future missions. Preflight calibration results will be described in a forthcoming second paper, and a detailed study of images will be presented in a third paper.
ABSTRACT
X-ray characterization measurements of the x-ray telescope (XRT) onboard the Astro-E satellite were carried out at the Institute of Space and Astronautical Science (Japan) x-ray beam facility by means of a raster scan with a narrow x-ray pencil beam. The on-axis half-power diameter (HPD) was evaluated to be 1.8?-2.2?, irrespective of the x-ray energy. The on-axis effective areas of the XRTs for x-ray imaging spectrometers (XISs) were approximately 440, 320, 240, and 170 cm(2) at energies of 1.49, 4.51, 8.04, and 9.44 keV, respectively. Those of the x-ray spectrometer (XRS) were larger by 5-10%. The replication method introduced for reflector production significantly improved the imaging capability of the Advanced Satellite for Cosmology and Astrophyics (ASCA) XRT, whose HPD is ~3.6?. The increase in the effective area by a factor of 1.5-2.5, depending upon the x-ray energy, compared with that of the ASCA, was brought about by mechanical scale up and longer focal lengths. The off-axis HPDs were almost the same as those obtained on the optical axis. The field of view is defined as the off-axis angle at which the effective area becomes half of the on-axis value. The diameter of the field of view was ~19? at 1.49 keV, decreasing with increasing x-ray energy, and became ~13? at 9.44 keV. The intensity of stray light and the distribution of this kind of light on the focal plane were measured at the large off-axis angles 30? and 60?. In the entire XIS field of view (25.4 mm x 25.4 mm), the intensity of the stray light caused by a pointlike x-ray source became at most 1% of the same pointlike source that was on the optical axis.
ABSTRACT
The dynamic aspects of circulating cytokines and cytokine modulators and their relationship with development of multiple organ failure (MOF) in patients with acute pancreatitis were analyzed. All cytokine and C-reactive protein levels in the circulation were higher than those in the MOF group. In particular, plasma concentrations of soluble tumor necrosis factor receptors (sTNF-RI and sTNF-RII) were significantly higher in patients with MOF than in those without even at admission. Furthermore, plasma concentrations of sTNF-Rs and interleukin-1 (IL-1) receptor antagonist (IL-1ra) were much higher than those of their counterparts, TNFalpha and IL-beta, respectively. These results suggest that the plasma concentrations of sTNF-Rs are useful predictors for the development of MOF, and actions of TNF-alpha and IL-1beta could be regulated by their modulators (soluble receptor and receptor antagonist, respectively) in the pathologic condition of severe acute pancreatitis.
Subject(s)
Cytokines/blood , Multiple Organ Failure/blood , Pancreatitis/blood , Acute Disease , Adolescent , Adult , C-Reactive Protein/analysis , Enzyme-Linked Immunosorbent Assay , Female , Humans , Interleukin 1 Receptor Antagonist Protein , Interleukin-1/blood , Interleukin-6/blood , Interleukin-8/blood , Male , Middle Aged , Pancreatitis/complications , Receptors, Tumor Necrosis Factor/blood , Sialoglycoproteins/blood , Tumor Necrosis Factor-alpha/analysisABSTRACT
p phenotype individuals lack both P(k) (Gb3) and P (Gb4) glycolipid antigens of the P blood group system. To explore the molecular basis for this phenotype, DNA sequences of Gb3 synthase (alpha1, 4-galactosyltransferase; alpha1,4Gal-T) in six p phenotype individuals from Japan and Sweden were analyzed. A missense mutation P251L and a nonsense mutation W261stop in three and one Japanese indivuiduals, respectively, and missense mutations M183K and G187D in one each of two Swedish p individuals were found, indicating that p individuals from Japan and Sweden have distinct and multiple homozygous point mutations in the coding region. In the function analysis of the mutated alpha1,4Gal-Ts by the transfection of the expression vectors, P251L and M183K mutations showed complete loss of enzyme function, and W261stop and G187D mutations resulted in the marginal activity. BLAST analysis of homologous sequences of alpha1, 4Gal-T revealed that three residues, Met(183), Gly(187), and Pro(251), at which missense mutations were found, were highly conserved among all species examined, suggesting their importance for the function of alpha1,4Gal-T.
Subject(s)
Galactosyltransferases/genetics , Genetics, Population , Mutation, Missense , P Blood-Group System/genetics , Amino Acid Sequence , Base Sequence , DNA Primers , Galactosyltransferases/chemistry , Humans , Japan , Molecular Sequence Data , Phenotype , Sequence Homology, Amino Acid , SwedenABSTRACT
By using a eukaryocytic cell expression cloning system, we have isolated cDNAs of the globoside synthase (beta1, 3-N-acetylgalactosaminyltransferase) gene. Mouse fibroblast L cells transfected with SV40 large T antigen and previously cloned Gb3/CD77 synthase cDNAs were co-transfected with a cDNA library prepared from mRNA from human kidney together with Forssman synthase cDNA, and Forssman antigen-positive cells were panned using an anti-Forssman monoclonal antibody. The isolated cDNAs contained a single open reading frame predicting a type II membrane protein with 351 amino acids. Surprisingly, the cDNA clones turned out to be identical with previously reported beta3Gal-T3, which had been cloned by sequence homology with other galactosyltransferases. Substrate specificity analysis with extracts from cDNA-transfected L cells confirmed that the gene product was actually beta1, 3-N-acetylgalactosaminyltransferase that specifically catalyzes the transfer of N-acetylgalactosamine onto globotriaosylceramide. Results of TLC immunostaining of neutral glycolipids from the cDNA-transfected cells also supported the identity of the newly synthesized component as globoside. The results show that glycosyltransferases apparently belonging to a single glycosyltransferase family do not necessarily catalyze reactions utilizing the same acceptor or even the same sugar donor. The globoside synthase gene was expressed in many tissues, such as heart, brain, testis, etc. We propose the designation beta3GalNAc-T1 for the cloned globoside synthase gene.
Subject(s)
N-Acetylgalactosaminyltransferases/genetics , Amino Acid Sequence , Carbohydrate Sequence , Cloning, Molecular , DNA, Complementary , Molecular Sequence Data , N-Acetylgalactosaminyltransferases/chemistry , N-Acetylgalactosaminyltransferases/metabolism , Sequence Homology, Amino Acid , Transfection , Polypeptide N-acetylgalactosaminyltransferaseABSTRACT
The expression cloning of a cDNA for globotriaosylceramide (Gb3)/CD77 synthase (alpha1,4-galactosyltransferase) was achieved using an anti-Gb3 antibody and mouse L cells as a recipient cell line for the transfection. The isolated cDNA clone designated pVTR1 predicted a type II membrane protein with 19 amino acids of cytoplasmic domain, 26 amino acids of transmembrane region, and a catalytic domain with 308 amino acids. Introduction of the cDNA clone into L cells resulted in the neosynthesis of Gb3/CD77, and the extracts of the transfectant cells showed alpha1, 4-galactosyltransferase activity only on lactosylceramide and galactosylceramide. In Northern blotting, a 2.3-kilobase mRNA was strongly expressed in heart, kidney, spleen, and placenta and weakly in colon, small intestine, and brain. Transfection of the cDNA into L cells resulted in the constitution of sensitivity to the apoptosis with Shiga-like toxins (verotoxins). Since Gb3/CD77 synthase initiates the synthesis of globo series glycolipids, the isolation of this cDNA will make possible further investigations into the function of its important series of glycolipids.
Subject(s)
Glycosphingolipids/biosynthesis , Trihexosylceramides/genetics , Trihexosylceramides/metabolism , Amino Acid Sequence , Animals , Base Sequence , Catalytic Domain , Cloning, Molecular , Gene Library , Humans , Kinetics , L Cells , Melanoma , Mice , Molecular Sequence Data , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Transfection , Trihexosylceramides/chemistry , Tumor Cells, CulturedABSTRACT
A novel member of the mouse CMP-NeuAc:beta-N-acetylgalactosaminide alpha2,6-sialyltransferase (ST6GalNAc) subfamily, designated ST6GalNAc VI, was identified by BLAST analysis of expressed sequence tags. The sequence of the cDNA clone of ST6GalNAc VI encoded a type II membrane protein with 43 amino acids composing the cytoplasmic domain, 21 amino acids composing the transmembrane region, and 269 amino acids composing the catalytic domain. The predicted amino acid sequence showed homology to the previously cloned ST6GalNAc III, IV, and V, with common amino acid sequences in sialyl motif L and S among these four enzymes. A fusion protein with protein A and extracts from L cells transfected with ST6GalNAc VI in an expression vector showed enzyme activity of alpha2,6-sialyltransferase for GM1b, GT1b, and GD1a but not toward glycoproteins. Thin layer chromatography-immunostaining revealed that the products were GD1alpha, GQ1balpha, and GT1aalpha. Northern blotting revealed that this gene was expressed in a wide range of mouse tissues such as colon, liver, heart, spleen, and brain. It is concluded that this enzyme is a novel sialyltransferase involved in the synthesis of alpha-series gangliosides in the nervous tissues and many other tissues.
Subject(s)
Gangliosides/biosynthesis , Sialyltransferases/genetics , Amino Acid Sequence , Animals , Base Sequence , Cells, Cultured , Cloning, Molecular , DNA, Complementary/isolation & purification , Mice , Molecular Sequence Data , RNA, Messenger/analysisABSTRACT
A novel member of the mouse CMP-NeuAc: beta-N-acetylgalactosaminide alpha2,6-sialyltransferase (ST6GalNAc) subfamily, designated ST6GalNAc V, was identified by BLAST analysis of expressed sequence tags. The sequence of the longest cDNA clone of ST6GalNAc V encoded a type II membrane protein with 8 amino acids comprising the cytoplasmic domain, 21 amino acids comprising the transmembrane region, and 306 amino acids comprising the catalytic domain. The predicted amino acid sequence showed homology to the previously cloned ST6GalNAc III and IV, with common amino acid sequences in sialyl motifs L and S among these three enzymes. Eleven CAG repeats were found in the stem region. A fusion protein with protein A and extracts from L cells transfected with ST6GalNAc V in a expression vector showed enzyme activity of alpha2,6-sialyltransferase almost exclusively for GM1b, but not toward glycoproteins. Sialidase treatment and thin layer chromatography immunostaining revealed that the product was GD1alpha. Northern blotting revealed that three transcripts of the gene were expressed specifically in brain tissues. It is concluded that this enzyme is involved in the synthesis of GD1alpha in the nervous tissues, and the CAG repeats may have implications in neurodegenerative diseases.
Subject(s)
Brain/enzymology , Glutamine , Sialyltransferases/genetics , Trinucleotide Repeats , Amino Acid Sequence , Animals , Base Sequence , Carbohydrate Sequence , Chickens , Cloning, Molecular , Conserved Sequence , Expressed Sequence Tags , Humans , Mice , Molecular Sequence Data , Oligosaccharides/metabolism , Rats , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Repetitive Sequences, Amino Acid , Sequence Alignment , Sequence Homology, Amino Acid , Sialyltransferases/chemistry , Sialyltransferases/metabolism , Substrate SpecificityABSTRACT
Progeroid type Ehlers-Danlos (E-D) syndrome was reported to be caused by defects in galactosyltransferase I (EC 2.4.1.133), which is involved in the synthesis of common linkage regions of proteoglycans. Recently, we isolated cDNA of the galactosyltransferase I (XGalT-1) (Okajima, T., Yoshida, K., Kondo, T., and Furukawa, K. (1999) J. Biol. Chem. 274, 22915-22918). Therefore, we analyzed mutations in this gene of a patient with progeroid type E-D syndrome by reverse transcription polymerase chain reaction and direct sequencing. Two changes of G and T to A and C at 186 and 206, respectively, were detected. Then, we determined the genomic DNA sequences encompassing the A186D and L206P mutations, revealing that the unaffected parents and two siblings were heterozygous for either one of the two different mutations and normal, while the patient had both of two different mutant genes. Enzymatic functions of cDNA clones of XGalT-1 containing the individual mutations were examined, elucidating that L206P clone completely lost the activity, while A186D retained approximately 50% or 10% of the activity when analyzed with extracts from cDNA transfectant cells or recombinant soluble enzymes, respectively. Moreover, L206P enzyme showed diffuse staining in the cytoplasm of transfectant cells, while the wild type or A186D clones showed Golgi pattern. These results indicated that the mutations in XGalT-1 were at least one of main molecular basis for progeroid type E-D syndrome.
Subject(s)
Ehlers-Danlos Syndrome/genetics , Galactosyltransferases/genetics , Progeria/genetics , Amino Acid Sequence , Animals , CHO Cells , Cloning, Molecular , Cricetinae , DNA Mutational Analysis , Fluorescent Antibody Technique , Galactosyltransferases/chemistry , Heterozygote , Humans , L Cells , Male , Mice , Molecular Sequence Data , Mutation , Sequence Alignment , TransfectionABSTRACT
A cDNA encoding a novel galactosyltransferase was identified based on BLAST analysis of expressed sequence tags, and the cDNA clones were isolated from a human melanoma line library. The new cDNA sequence encoded a type II membrane protein with 327 amino acid sequence and showed 38% homology to the Caenorhabditis elegans sqv-3 gene involved in the vulval invagination and oocyte development. Extracts from L cells transfected with the galactosyltransferase cDNA in an expression vector and a fusion protein with protein A exhibited marked galactosyltransferase activity specific for p-nitrophenyl-beta-D-xylopyranoside. Moreover, transfection with the cloned cDNA restored glycosaminoglycan synthesis of galactosyltransferase I-deficient Chinese hamster ovary mutant pgsB-761 cells. Analysis of the enzyme product by beta-galactosidase digestion, mass spectroscopy, and NMR spectroscopy revealed that the reaction product was formed via beta-1,4 linkage, indicating that the enzyme is galactosyltransferase I (UDP-galactose:O-beta-D-xylosylprotein 4-beta-D-galactosyltransferase, EC 2.4.1.133) involved in the synthesis of the glycosaminoglycan-protein linkage region of proteoglycans.
Subject(s)
Caenorhabditis elegans Proteins , Caenorhabditis elegans/genetics , Galactosyltransferases/genetics , Glycosaminoglycans/metabolism , Glycosyltransferases/genetics , Helminth Proteins/genetics , Proteoglycans/biosynthesis , Amino Acid Sequence , Animals , Base Sequence , CHO Cells , Cloning, Molecular , Cricetinae , DNA, Complementary , Galactosyltransferases/chemistry , Galactosyltransferases/metabolism , Glycosyltransferases/metabolism , Helminth Proteins/metabolism , Humans , Molecular Sequence Data , Proteoglycans/chemistry , Sequence Homology, Amino AcidABSTRACT
The patient was a woman of forty-eight. Liver dysfunction was pointed out at the age of forty-five. She was admitted to hospital because of her hyperthyroidism. Her palmar skin was wet and her fingers were swollen like sausages. She had a diffuse and elastic hard goiter with a rough surface. The serum levels of free T3 (9.6 pg/mL) and free T4 (3.76 ng/dL) were high and that of TSH (0.11 microU/mL) was low. The activity of TSH-binding inhibitory immunoglobulin (TBII) was 89%. The uptake rate of 123I to the thyroid was 55.1% and the uptake pattern was nearly diffuse. The goiter was proved to contain several nodules by ultrasonography, but aspiration cytology showed no malignant cells. She was diagnosed to have Graves' disease with adenomatous goiter. She also had high ALT (34 IU/L) and gamma-globulin (1.97 g/dL). She had positive antinuclear antibody (speckled type), positive anti-ribosomal nuclear protein antibody, and positive LE cell phenomenon. The liver biopsy revealed mononuclear cell infiltration with fibrosis in the portal area. These data indicated that she also had autoimmune hepatitis (AIH) and mixed connective tissue disease (MCTD). The analysis of human leukocyte antigen (HLA) showed positive A11 which had been reported to relate to Graves' disease, and positive DR4 which had been reported to relate to AIH and MCTD. These results suggested that HLA would determine susceptibility to three distinct autoimmune diseases in this case.