Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q07644 (polypeptide)
 72,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The fetal globin genes G gamma and A gamma from one chromosome of a chimpanzee (Pan troglodytes) were sequenced and found to be closely similar to the corresponding genes of man and the gorilla. These genes contain identical promoter and termination signals and have exons 1 and 2 separated by the conserved short intron 1 (122 bp) and exons 2 and 3 separated by the more rapidly evolving, larger intron 2 (893 bp and 887 bp in chimpanzee G gamma and A gamma, respectively). Each intron 2 has a stretch of simple sequence DNA (TG)n serving possibly as a "hot spot" for recombination. The two chimpanzee genes encode polypeptide chains that differ only at position 136 (glycine in G gamma and alanine in A gamma) and that are identical to the corresponding human chains, which have aspartic acid at position 73 and lysine at 104 in contrast to glycine and arginine at these respective positions of the gorilla A gamma chain. Phylogenetic analysis by the parsimony method revealed four silent (synonymous) base substitutions in evolutionary descent of the chimpanzee G gamma and A gamma codons and none in the human and gorilla codons. These Homininae (Pan, Homo, Gorilla) coding sequences evolved at one-tenth the average mammalian rate for nonsynonymous and one-fourth that for synonymous substitutions. Three sequence regions that were affected by gene conversions between chimpanzee G gamma and A gamma loci were identified: one extended 3' of the hot spot with G gamma replaced by the A gamma sequence, another extended 5' of the hot spot with A gamma replaced by G gamma, and the third conversion extended from the 5' flanking to the 5' end of intron 2, with G gamma replaced here by the A gamma sequence. A conversion similar to this third one has occurred independently in the descent of the gorilla genes. The four previously identified conversions, labeled C1-C4 (Scott et al. 1984), were substantiated with the addition of the chimpanzee genes to our analysis (C1 being shared by all three hominines and C2, C3, and C4 being found only in humans). Thus, the fetal genes from all three of these hominine species have been active in gene conversions during the descent of each species.
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PMID:Chimpanzee fetal G gamma and A gamma globin gene nucleotide sequences provide further evidence of gene conversions in hominine evolution. 387 Aug 67

The amino acid sequence of protein Z has been determined from sequence analysis performed on fragments obtained by chemical and enzymatic degradations. The polypeptide consists of a single chain containing 396 amino acid residues (Mr 43 677). Comparison with the vitamin K-dependent plasma proteins reveals an extensive homology. The N-terminal part, containing 13 gamma-carboxyglutamic acid and one beta-hydroxyaspartic acid residue, is extensively homologous to and of similar length to the light chain of factor X. The remainder of protein Z is homologous to the serine proteases and of similar size to the heavy chain of factor Xa, but of the active site residues only aspartic acid-102 is present. Histidine-57 and serine-195 are replaced in protein Z by threonine and alanine, respectively. The physiological function of protein Z is still uncertain.
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PMID:Amino acid sequence of bovine protein Z: a vitamin K-dependent serine protease homolog. 388 70

Experiments were designed to produce and characterize a polyclonal antibody directed against mouse dentine phosphoprotein, the major non-collagenous protein of the dentine extracellular matrix. Dental extracellular matrix proteins from 2-day-postnatal Swiss-Webster-mouse tooth organs were extracted with 0.5 M-acetic acid, followed by 4 M-guanidinium chloride/0.5 M-EDTA. Mouse dentine phosphoprotein yields were further increased by precipitation with 1 M-CaCl2. Final purification was achieved by excising and eluting dentine phosphoprotein polypeptide bands from preparative sodium dodecyl sulphate/urea/polyacrylamide gels. Mouse dentine phosphoprotein is a single component of approx. 72 kDa and has a characteristic amino acid composition of 33% aspartic acid and 55% serine/phosphoserine. A polyclonal antibody was raised in rabbits against purified mouse dentine phosphoprotein and was shown to be monospecific by enzyme-linked immunoabsorbent, dot-immunobinding and 'Western transfer' assays. This antibody was used to detect the expression and localization of dentine phosphoprotein in 1-day-postnatal mouse tooth organs. This antigen was localized intracellularly within the monolayer of odontoblasts, which line the perimeter of the dental papilla mesenchyme, and within the odontoblastic cell processes, which traverse the predentine matrix. Newly forming mineralized dentine matrix was also cross-reactive with the dentine phosphoprotein specific antibody. The non-mineralized predentine matrix did not contain any detectable cross-reactive antigens.
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PMID:Production and characterization of antibodies against murine dentine phosphoprotein. 391 47

The enzyme asparaginase, which hydrolyses asparagine to aspartic acid, inhibited cell-free protein synthesis by reticulocyte lysates. The inhibition was rapid and complete when sufficient enzyme was added but could be prevented or reversed by the addition of asparagine. The initial effect of asparaginase appears to be a block in polypeptide chain elongation due to asparagine deprivation, but there are some indications that prolonged incubation under these conditions may give rise to a secondary decrease in initiation of protein synthesis.
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PMID:Control of protein synthesis by amino acid supply. The effect of asparagine deprivation on the translation of messenger RNA in reticulocyte lysates. 394 Aug 84

The neutral histidine-rich polypeptide (HRP) from human parotid secretion was isolated by ion-exchange and gel-filtration chromatography. The complete amino acid sequence determined by automated Edman degradation of the protein, tryptic and Staphylococcus aureus V8 protease peptides, and digestion with carboxypeptidase A is: (Formula: see text) where Pse represents phosphoserine. The polypeptide contains 38 residues and has Mr 4929. The charged amino acids predominate with 7 histidine, 4 arginine, 3 lysine, 3 aspartic acid, 3 glutamic acid residues, and 1 phosphoserine. Assuming minimal charge contributions from histidine and one negative charge from phosphoserine at pH 7, the net charge of HRP is balanced by an equal contribution of basic and acidic residues. Furthermore, the distribution of hydrophilic and hydrophobic residues along the polypeptide chain indicates that there is no structural polarity. The polypeptide lacks threonine, alanine, valine, cysteine, methionine, and isoleucine. HRP did not display sequence similarity with any protein sequence in the National Biomedical Research Foundation Data Bank. HRP is an active inhibitor of hydroxyapatite crystal growth from solutions supersaturated with respect to calcium phosphate salts and therefore must play a role in the stabilization of mineral-solute interactions in oral fluid. In addition, HRP is a potent inhibitor of Candida albicans germination and therefore may be a significant component of the antimicrobial host defense system in the oral cavity.
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PMID:The primary structure and functional characterization of the neutral histidine-rich polypeptide from human parotid secretion. 394 83

The genetic locus specifying rifampicin-resistance (RifR) in a vaccinia virus mutant has been localized by marker rescue analysis (J. Tartaglia and E. Paoletti (1985) Virology 147, 394-404). The mutation was defined by DNA sequence analysis as an AT to GC transition occurring 56 bp to the left of the unique XhoI site within HindIII D. The point mutation resulted in an asparagine to aspartic acid substitution 60 amino acids from the predicted C-terminus. Specific DNA probes were used to characterize the RifR designated gene at the transcriptional and translational levels. This region is transcriptionally active only after vaccinia virus DNA synthesis, but not in the presence of cytosine arabinoside suggesting that the RifR function is a late gene product. Translation of hybrid selected RNA to DNA surrounding the mutant marker directed the synthesis of a polypeptide with an apparent mol wt of 63 kDa. Transcriptional and translational mapping studies showed that the mRNA encoding this 63-kDa polypeptide was initiated approximately 460 bp to the right of the HindIII D-A junction and was transcribed in a leftward direction into the HindIII D region.
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PMID:Vaccinia virus rifampicin-resistance locus specifies a late 63,000 Da gene product. 395 88

The size distribution of the 20 aminoacyl-tRNA synthetases from wild-type Chinese hamster ovary (CHO) cells and from the mutant cell line tsH1, containing a temperature-sensitive leucyl-tRNA synthetase, was determined by gel filtration. Nine aminoacyl-tRNA synthetases, specific for arginine, aspartic acid, glutamic acid, glutamine, isoleucine, leucine, lysine, methionine and proline, which coeluted as high-Mr entities (Mr approximately 1.2 X 10(6)), were further co-purified to yield a multienzyme complex, the polypeptide composition of which was identical to that previously determined for the complex from rabbit liver. Immunoprecipitates obtained from crude extracts of wild-type and tsH1 mutant cells, using specific antibodies directed to the lysyl-tRNA or methionyl-tRNA synthetase components of the complex, displayed the same polypeptide compositions as that of the purified complex, thereby establishing the heterotypic nature of this complex. Although the activity of leucyl-tRNA synthetase from the mutant cells, grown at a permissive temperature, was low compared to that from the wild-type, the polypeptide of Mr 129 000, corresponding to this enzyme, was present in similar amounts and occurred exclusively as a component of the high-Mr complex. Finally, we report that attempts to demonstrate phosphorylation of the components of the complex from cultured CHO, HeLa and C3 cells were unsuccessful.
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PMID:A complex from cultured Chinese hamster ovary cells containing nine aminoacyl-tRNA synthetases. Thermolabile leucyl-tRNA synthetase from the tsH1 mutant cell line is an integral component of this complex. 397 83

The enzyme from almond that catalyzes the hydrolysis of the N-glycosidic linkage between asparagine and the oligosaccharide chain of glycopeptides and glycoproteins has been variously termed an N-glycosidase and an amidase enzyme. Using turkey ovomucoid glycopeptide as a substrate for the enzyme, we followed the hydrolysis reaction by 1H NMR spectroscopy. These kinetic data revealed a rapid hydrolysis of the substrate but a delayed appearance of the final product. This implied that an intermediate, most likely a 1-aminooligosaccharide, was formed during the reaction. Identification of the intermediate as a 1-beta-amino-N-acetylglucosamine-oligosaccharide was achieved by trapping it as the 1-acetamido derivative using acetic anhydride and subsequent analysis by 1H NMR. The data conclusively demonstrate that the enzyme catalyzes the hydrolysis of the glycopeptide to form an aspartic acid-containing polypeptide and an intermediate oligosaccharide amine. The latter derivative is hydrolyzed nonenzymatically to yield the final carbohydrate product. Thus, the enzyme is in fact an amidohydrolase (amidase) and not an N-glycosidase. The trivial name glycopeptidylamidase is suggested.
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PMID:1H NMR evidence that almond "peptide: N-glycosidase" is an amidase. Kinetic data and trapping of the intermediate. 406 79

The synthetic polypeptide, poly-L-aspartic acid (PAA, mol. wt = 20,000) has been used as a macromolecular carrier for doxorubicin. The drug may be released in vivo through hydrolysis of the ester linkage formed between the carboxyl groups of the polymer and the drug side chain. PAA has been found to be a suitable carrier since it is a soluble, biodegradable, multivalent and nontoxic polymer. The toxicity and the therapeutic efficacy of free and polymer-linked doxorubicin have been evaluated in normal and tumour-bearing mice, using a variety of experimental tumour systems. In studies on single and multiple drug administration, the results indicated that the polymeric derivative of doxorubicin had approximately 3-fold lower toxicity than did free drug. In addition, the severity of specific toxic effects, including cardio- and vesicant toxicity, were appreciably reduced following conjugation to PAA. The doxorubicin-PAA conjugate gave similar or rather greater therapeutic effects than free drug at less toxic doses. This effect, more evident in the highly sensitive tumours, suggests an improvement of the therapeutic index of the polymer-linked drug.
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PMID:Poly-L-aspartic acid as a carrier for doxorubicin: a comparative in vivo study of free and polymer-bound drug. 407 38

The carbohydrate content of an A myeloma globulin was investigated. The carbohydrate content was found to be unchanged when the protein was isolated from the patient over a period of 18 months. The various polymeric forms of the protein contained similar proportions of carbohydrate. The A myeloma globulin contained approx. 2 residues of 6-deoxy-l-galactose (l-fucose), 14-15 of d-mannose, 12-13 of d-galactose, 12-13 of 2-acetamido-2-deoxy-d-glucose (N-acetyl-d-glucosamine), 6 of 2-acetamido-2-deoxy-d-galactose (N-acetyl-d-galactosamine) and 5 of N-acetylneuraminic acid (sialic acid), and these were distributed between six oligosaccharide units all of which were present on the heavy polypeptide chains. The oligosaccharide units showed two kinds of heterogeneity, which have been termed central and peripheral. Central heterogeneity was shown by the presence of three completely different core units, which had the following compositions: (1) 3 residues of d-galactose and 3 of 2-acetamido-2-deoxy-d-galactose, joined to protein by an O-glycosidic linkage between acetamidohexose and serine; (2) 3 residues of d-mannose, 2 of d-galactose and 3 of 2-acetamido-2-deoxy-d-glucose, joined to protein by an N-glycosidic linkage between acetamidohexose and aspartic acid; (3) 4 residues of d-mannose and 3 of 2-acetamido-2-deoxy-d-glucose with a linkage similar to that in (2). The core oligosaccharide units showed peripheral heterogeneity in the attachment of 6-deoxy-l-galactose, 2-acetamido-2-deoxy-d-glucose and N-acetylneuraminic acid. Tentative structures are proposed for these various types of oligosaccharide unit. Glycopeptides were isolated in which the sialic acid content exceeded that of d-galactose. Explanations are given for the electrophoretic mobility and staining characteristics of the various glycopeptides.
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PMID:Investigations on the oligosaccharide units of an A myeloma globulin. 417 99


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