UNIPROT:Q07644 - FACTA Search

Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Target Concepts:

Query: UNIPROT:Q07644 (polypeptide)
72,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The complete nucleotide sequence has been determined for a lambda gt11 cDNA clone (lambda AG18) containing the full-length coding region for the mature lysosomal form of human alpha-galactosidase A (alpha-Gal A; EC 3.2.1.22). The lambda AG18 insert contained a 1226-base-pair sequence with an open reading frame encoding 398 amino acids of the mature polypeptide (predicted Mr = 45,356) and the last 5 amino acids of the propeptide sequence. The poly(A) signals AATACA and ATTAAA occurred 28 and 11 nucleotides prior to the TAA stop codon, respectively. There was no 3' untranslated region as the poly(A) sequence immediately followed the TAA termination codon; a second independently cloned cDNA confirmed this finding. The predicted amino acid sequence was colinear with 86 nonoverlapping residues (22% of the mature subunit) determined by microsequencing amino-terminal, tryptic, and cyanogen bromide peptides of the purified mature enzyme. Four potential N-glycosylation sites were identified, all of which occurred at predicted beta turns in hydrophilic regions of secondary structure. RNA transfer hybridization analysis of HeLa poly(A)+ RNA demonstrated a single 1.45-kilobase band whose signal was decreased by prior immunoabsorption of polysomes with monospecific alpha-Gal A antibodies. Searches of nucleic acid and protein data bases did not reveal significant homology even with the limited sequences available for mammalian lysosomal enzymes.
...
PMID:Human alpha-galactosidase A: nucleotide sequence of a cDNA clone encoding the mature enzyme. 301 15

The major outer layer protein, VP7, of the simian rotavirus SA11 has been synthesized in Escherichia coli, under the control of the lac promoter, as a fusion polypeptide with beta-galactosidase (beta Gal). The viral protein in the hybrid polypeptide is missing its N-terminal hydrophobic region and 26 amino acids (aa) at its C-terminus; it is flanked at both ends by beta Gal sequences. We have purified the hybrid 145-kDa protein by affinity chromatography using a column specific for beta Gal. Unexpectedly, a second protein of 118-kDa was also specifically bound to the column. N-terminal aa sequence analysis of these two proteins showed that the 145-kDa protein represented the expected fusion product, whereas the 118-kDa protein was apparently the result of initiation of translation at an internal site close to the 3' end of the viral sequence, in the chimeric mRNA. Each of the two polypeptides represented about 2 to 3% of the total protein of the recombinant-plasmid-carrying bacteria. When a bacterial lysate enriched for the hybrid polypeptides was injected into mice, it induced neutralizing antibodies to SA11 rotavirus.
...
PMID:Synthesis of the outer-capsid glycoprotein of the simian rotavirus SA11 in Escherichia coli. 303 Aug 91

Regardless of the A, B, H, Le(a), Le(b), I and i activity, purified water-soluble blood group glycoproteins from human ovarian cyst fluid have a similar overall structure. They are polydisperse macromolecules (Mr 2.0 x 10(5) to several million) of similar composition (75 to 85% carbohydrate, 15 to 20% protein) and consist of multiple heterosaccharide side chains attached by an O-glycosidic linkage at their internal reducing ends to serine or threonine of the polypeptide backbone. About 90% of these carbohydrate side chains range in size from one to less than twenty-four sugar residues (twelve sugars in the internal structure and twelve key sugars specific as blood group determinants). Three-fourths of these side chains contain fewer than twelve sugars. A generalized blood group active carbohydrate chain is shown above. Three disaccharide units-Type I chain (Gal beta 1----3GlcNAc beta 1----3), Type II chain (Gal beta 1----4GlcNAc beta 1----6) and T determinant [Gal beta 1----3GalNAc alpha 1----Ser(Thr)]-are used to elucidate the internal structure of the carbohydrate chains. The complete internal structure is considered to have a core structure with four branches, to which the blood group key sugars are attached at the appropriate locations. The core structure is a tetrasaccharide, composed of one unit of Type I chain at the nonreducing end and the T determinant at the other end, linked to Ser or Thr of the protein moiety. Branch I is Type I chain and Branch II is Type II chain. They are linked to Gal at the nonreducing end of the core structure. Branch III is usually a Type II chain, but may sometimes be a Type I chain, linked to the GalNAc of the reducing end. The length of Branch III can be increased by adding one or more monosaccharides of Type I chain sequence such as Gal beta 1----3GlcNAc beta 1----3Gal beta 1----4GlcNAc beta 1----6GalNAc alpha 1----Ser(Thr), a combination of Type I and Type II chains. A new Branch IV is made up of Type II chain, which in turn is linked to the Gal end of the T determinant. The Type II chains react with the antibody to the type XIV pneumococcal capsular polysaccharide and with the anti-I(Ma) cold agglutinin.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Structural concepts of the human blood group A, B, H, Le(a), Le(b), I and i active glycoproteins purified from human ovarian cyst fluid. 305 18

The carbohydrate components of combined alpha-subunits of urinary hCG and human pituitary LH (hLH), FSH (hFSH), and TSH (hTSH), each derived from the intact hormone, were studied by direct sugar analysis and methylation analysis. The methods provide a complete survey of the structural elements contained in the complex sugars associated with these glycoproteins, but do not establish the sugar sequences or anomeric configurations of glycosidic bonds. By analogy to N-linked oligosaccharides that occur in many glycoproteins, the data suggest distinct structural features for carbohydrates of alpha-subunits combined with beta-subunits. hCG alpha contains biantennary asparagine-linked chains terminated by either NeuAc alpha 2-3Gal beta 1- or GlcNAc beta 1-2 Man alpha 1- and lacks fucose. hTSH alpha contains biantennary chains with the same termini as hCG alpha plus terminal R-O-4GalNAc and a fucosyl residue linked alpha 1-6 to the inner GlcNAc residue of the N-linked chitobiosyl core. hLH alpha may contain some high mannose chains, but primarily contains biantennary chains terminated by NeuAc alpha 2-3(6)Gal beta 1-, GlcNAc beta 1-, GalNac-1-, R'-O-6GlcNAc-1-, and R"-0-2Man-1-plus a fucosyl residue linked alpha 1-6 to the inner GlcNAc residue of the N-linked chitobiosyl core. hFSH alpha contains more complicated structures that probably include a bisecting GlcNAc residue linked beta 1-4 to a 3,6-di-O-substituted core mannosyl residue, and terminal NeuAc alpha 2-3Gal beta 1-4(+/- Fuc alpha 1-3)GlcNAc-1, Gal beta 1-4(+/- Fuc alpha 1-3)GlcNAc-1-, R"'-O-GalNAc-1-, and GalNAc-1. In addition, the presence of 2,4-di-O-substituted mannose in hFSH alpha indicates that it contains triantennary chains. The identities of the R; R', R", and R"' groups were not determined, but recent studies of glycoprotein hormones suggest that they may be sulfate groups. Our results demonstrate differential glycosylation of virtually identical polypeptide hormone alpha-subunits produced in the same organ or perhaps even in the same cell.
...
PMID:Differences in the carbohydrate moieties of the common alpha-subunits of human chorionic gonadotropin, luteinizing hormone, follicle-stimulating hormone, and thyrotropin: preliminary structural inferences from direct methylation analysis. 309 95

A human Hanganutziu-Deicher (H-D) serum reacted with N-glycolylneuraminic acid (NeuGc)-containing gangliosides and glycoproteins isolated from bovine erythrocyte membranes. Three populations of H-D antibodies were identified in the human H-D serum. One population very likely recognized the NeuGc-Gal sequence; a second population appears to recognize additional sugars in the oligosaccharide sequence, e.g. NeuGc-Gal-GlcNAc; while a third population may also recognize polypeptide determinants in addition to the NeuGc-Gal-GlcNAc sequence. The H-D serum distinguished two high mol. wt glycoproteins (HMGP I and II) present in crude extracts of bovine erythrocyte membranes. These glycoproteins were separated by repetitive fractionation on Sephacryl S-1000 in the presence of urea and their composition determined.
...
PMID:Interaction of bovine erythrocyte N-glycolylneuraminic acid-containing gangliosides and glycoproteins with a human Hanganutziu-Deicher serum. 309 77

Whole rat liver nuclei were reacted with UDP-[14C]galactose in the presence of bovine beta(1----4) galactosyltransferase. The reaction mixture was electrophoresed on a reducing sodium dodecyl sulfate-polyacrylamide gel. Autoradiograms of the gel demonstrated a major labeled broad band migrating with an apparent molecular weight of 65,000-66,000. A number of other less prominently labeled bands were also present. The labeled 65,000-66,000 band when cut from the gel and subjected to alkaline reduction while in the gel matrix exclusively yielded a 14C-labeled disaccharide that co-migrated with a [14C]Gal-GlcNAcol standard in descending paper chromatography. Treatment of this disaccharide with beta-galactosidase (beta-D-galactoside galactohydrolase; EC 3.2.1.23) from Aspergillus niger removed all the [14C]galactose label. Treatment of the labeled 65,000-66,000 polypeptide with Endoglycosidase F, however, did not remove the [14C]galactose label. Western transfer blots of sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels performed with horseradish peroxidase-labeled succinyl wheat germ agglutinin, a lectin specific for GlcNAc, on unlabeled nuclei revealed a dominant band at 63,000-64,000. Subjecting 14C-labeled nuclei to this procedure resulted in a shift of the major horseradish peroxidase-labeled succinyl wheat germ agglutinin band to 65,000-66,000. The shifted band was coincident with the [14C]galactose band as visualized on an autoradiogram. A survey of other rat tissue nuclei revealed the same spectrum of [14C]galactose acceptor proteins with a dominant 65,000-66,000 galactose-labeled band.
...
PMID:A nuclear specific glycoprotein representative of a unique pattern of glycosylation. 310 May 29

Maltase-glucoamylase (MGA) was immunoprecipitated from detergent extracts of brush border membranes of the human small intestinal mucosa. Electrophoretic analysis of the precipitates under denaturing conditions revealed a single polypeptide of Mr = 335,000 in the presence or absence of reducing agents. Cross-linking of brush border membranes with the homobifunctional reagent dithiobis(succinimidylpropionate) did not result in considerable changes in the electrophoretic pattern of MGA. In contrast, aminopeptidase N, used in these studies as a control glycoprotein of the brush border membrane revealed dimeric structures of its single subunit in the presence of dithiobis(succinimidylpropionate). These data suggest that MGA is expressed in the human small intestinal brush border as a monomeric polypeptide. The biosynthesis of MGA was studied by pulse-labeling of human intestinal biopsy specimens or mucosal explants in organ culture. Continuous labeling with [35S]methionine for 30 min revealed a single polypeptide high mannose precursor of Mr = 285,000 (MGAh) which matures after 4 h of labeling to the Mr = 335,000 as judged by the susceptibility of these two forms to endo-beta-N-acetylglucosaminidase H. Owing to the absence of pancreatic secretions in the culture medium and the isolation of an identical species from nonlabeled mucosa, this result indicates that the Mr = 335,000 does not undergo an in situ extracellular cleavage by intraluminal proteases. Further, biosynthetically labeled, intracellularly cleaved polypeptides corresponding to the high mannose precursor or mature forms of MGA were not detected. The mature form of MGA (MGAm) bears in addition to N-linked glycans also O-glycosidically linked oligosaccharides. In fact, endo-beta-N-acetylglucosaminidase F/glycopeptidase F treatment of MGAm followed by chemical deglycosylation with trifluoromethanesulfonic acid revealed approximately 35,000 daltons of O-linked sugars. Furthermore, MGAm as well as its N-linked sugars-depleted form bound to Helix pomatia lectin which has specificity toward Gal-GalNAc structures. In addition, the data were suggestive of a post-translational O-glycosylation of the molecule since (i) the high mannose precursor of MGA did not bind to H. pomatia lectin and (ii) its endo-beta-N-acetylglucosaminidase H or endo-beta-N-acetylglucosaminidase F/glycopeptidase F form displayed an apparent molecular weight similar to that obtained upon endo-beta-N-acetylglucosaminidase F/glycopeptidase F/trifluoromethanesulfonic acid deglycosylation. Finally, pulse-chase experiments revealed a relatively slow rate of post-translational processing of MGA in comparison to aminopeptidase N.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Structure, biosynthesis, and glycosylation of human small intestinal maltase-glucoamylase. 314 29

The Rhizobium meliloti (Rm) lacZ gene provides a convenient model to investigate patterns of gene regulation in these agronomically important bacteria. A gene encoding beta-galactosidase (beta Gal) activity was cloned from R. meliloti by complementing a lactose-negative Escherichia coli mutant. A series of Sau3A subclones was generated in pBR322, and the coding region for the beta Gal-coding gene was localized to a 2.4-kb core fragment. In E. coli 'maxicells', these lacZ subclones produced a 79-kDa polypeptide, irrespective of the fragment size demonstrating that the translation initiation signal(s) are located on the 2.4-kb fragment. Transposon Tn5 mutagenesis and BAL 31 deletion analysis showed that the expression of the Rm lacZ gene in E. coli was dependent on the tetracycline-resistance promoter of pBR322. The cloned sequence was required for beta Gal synthesis in Rhizobium since mutants generated by reverse genetics lack this enzyme and were specifically defective in lactose catabolism.
...
PMID:Cloning and characterization of a novel beta-galactosidase-coding gene from Rhizobium meliloti. 314 8

The regulation of the protein kinase activity responsible for the phosphorylation of the light-harvesting complex of photosystem II (LHCII) 27-kDa polypeptide involved in the State I-State II transitions in Acetabularia thylakoids was investigated. The LHCII kinase of isolated thylakoids retains its activity in absence of light-driven electron flow or reductants added in the dark. However, the kinase is reversibly inactivated by addition of oxidants in vitro or by far red (710 nm) light in vivo. Inhibitors of the quinol oxidase site of the cytochrome b6.f complex inactivate the LHCII kinase in the dark, and also in the light, or in presence of duroquinol when the plastoquinone pool is reduced. Inhibitors of the quinone reductase site of the b6.f complex have practically no effect in the dark and stimulate the kinase activity in the light. Based on these data and on our previous report, showing specific loss of LHCII kinase activity in a Lemna mutant lacking the cytochrome b6.f complex (Gal, A., Shahak, Y., Schuster, G., and Ohad, I. (1987) FEBS Lett. 221, 205-210), we propose that the activity of the LHCII kinase is regulated by the redox state of a cytochrome b6.f complex component(s) which responds to the balance of electron flow from photosystem II via the plastoquinone pool to photosystem I.
...
PMID:Role of the cytochrome b6.f complex in the redox-controlled activity of Acetabularia thylakoid protein kinase. 328 40

The heat-labile enterotoxins of Vibrio cholerae and Escherichia coli are related in structure and function. They are oligomers consisting of A and B polypeptide subunits. They bind to gangliosides, and they activate adenylate cyclase. The toxins form two antigenically distinct groups; members of each group cross-react but are not necessarily identical. Serogroup I includes cholera toxin (CT) and type I heat-labile enterotoxin (LT-I) of E. coli. LTh-I and LTp-I are antigenic variants of LT-I produced by strains of E. coli from humans and pigs, respectively. Serogroup II contains the type II heat-labile enterotoxin (LT-II) of E. coli. Two antigenic variants designated LT-IIa and LT-IIb have been described. The binding of CT, LTh-I, LT-IIa, and LT-IIb to gangliosides was analyzed by immunostaining thin-layer chromatograms and by solid-phase radioimmunoassay. The four toxins have different glycolipid-binding specificities. LTh-I and CT bind strongly to ganglioside GM1 and less strongly to ganglioside GD1b. However, LTh-I, unlike CT, also binds weakly to GM2 and asialo GM1. LTh-I, like CT, probably binds to the terminal sugar sequence Gal beta 1-3GalNAc beta 1-4(NeuAc alpha 2-3)Gal . . ., where GalNAc is N-acetylgalactosamine and NeuAc is N-acetylneuraminic acid. LT-IIa probably binds to the same sugar sequence to which CT and LTh-I bind, with the additional contribution to binding of a second NeuAc as in GD1b and GD2. Also, LT-IIa must bind the Gal beta 1-3GalNAc . . . sequence in such a way that its binding is relatively unaffected by attachment of NeuAc to the terminal galactose residue as in GD1a, GT1b, and GQ1b. LT-IIb probably binds to the terminal sugar sequence NeuAc alpha 2-3Gal beta 1-4GalNAc . . ., as it binds to gangliosides GD1a and GT1b but not to GM1.
...
PMID:Comparison of the carbohydrate-binding specificities of cholera toxin and Escherichia coli heat-labile enterotoxins LTh-I, LT-IIa, and LT-IIb. 329 Jan 6

<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>