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)

A basic protein has been isolated and purified from the stratum corneum of newborn rat epidermis. This protein is referred to as stratum corneum basic protein. It was purified by ion-exchange chromatography on DE-52 and CM-52 cellulose. The protein has a molecular weight of 50 000 on sodium dodecyl sulfate-polyacrylamide gels. It is composed of one polypeptide chain and contains no detectable carbohydrate. The protein has an isoelectric point in the range of pH 9-10, but decomposes during isoelectric focusing giving rise to a polypeptide of less than 10 000 daltons. Amino acid analysis reveals high quantities of glutamic acid, glycine, serine, arginine and relatively high levels of histidine, with these five amino acids composing 74% of the total residues. The amino acid analysis is very similar to histidine-containing keratohyalin proteins isolated from the granular layer of epidermis by several investigators. The stratum corneum basic protein differs from fibrous proteins isolated from the same cell layer with respect to net charge, amino acid composition, and molecular weight. The protein does not react with antibody to the fibrous protein. The basic protein has properties which are consistent with its possible function as a stratum corneum interfilamentous matrix protein.
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PMID:Purification and characterization of a basic protein from the stratum corneum of mammalian epidermis. 84 56

A phosphorylated polypeptide (E4) of molecular weight 5000-6000, has been isolated from bovine embryonic enamel by Bio-Gel P-10 gel filtration and DE-52 ion-exchange chromatography. The peptide contains three serine residues all of which are phosphorylated. All three O-phosphoserine residues are in glutamic acid-O-phosphoserine-tyrosine sequences that are distributed relatively evenly along the polypeptide chain. Although it was not possible to sequence the entire polypeptide chain directly by automatic peptide sequencing, a partial sequence and peptide map was constructed on the basis of the sequence and composition of peptides derived by cyanogen bromide, trypsin and chymotrypsin digestion. The presence of glutamic acid, tyrosine and leucine adjacent to and near the O-phosphoserine residues may be important in calcium binding and in mineralization.
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PMID:Isolation, characterization and partial amino acid sequence of a phosphorylated polypeptide (E4) from bovine embryonic dental enamel. 88 76

Earlier studies from our laboratory demonstrated that the terpolymer of L-glutamic acid, L-alanine, and L-tyrpsine (GAT) stimulated the development of T cells capable of specifically suppressing the antibody responses in vivo and in vitro of nonresponder strains (bearing the H-2(s), H-2(q), and H-2(p) haplotypes) to GAT complexed with an immunogenic carrier, methylated bovine serum albumin, MBSA (1,2). We then extended these findings to another antigen, the copolymer of L-glutamic acid and L-tyrosine (GT). None of 19 inbred or congenic resistant mouse strains developed antibody responses to GT after immunization with this synthetic polypeptide in adjuvants. All the strains investigated, however, developed IgG plaque-forming cells (PFC) primary responses to GT complexed with MBSA (3). This permitted us to determine that: (a) preimmunization with GT suppressed the response to GT-MBSA in certain but not in all strains; (b) the suppression could be transferred by thymocytes and spleen cells from GT-primed animals; (c) the development of GT-specific suppressor cells is under dominant control of H-2- linked gene(s) which have been designated specific immune suppressor genes (Is genes); (d) the Is genes are antigen specific since GAT-MBSA responses are suppressed by GAT in strains carrying the H-2(q) haplotype, while GT-MBSA responses are not suppressed by the related polymer GT in these same strains (3,4). The experiments reported in this study map the Is genes responsible for GT-specific suppression within the H-2 complex. The data indicate that the K and D loci are not concerned with GT-specific suppression, and that this phenomenon is controlled by complementing or interacting genes which map on either side of cross-over events between the IB and IC subregions.
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PMID:Genetic control of specific immune suppression. III. Mapping of H-2 complex complementing genes controlling immune suppression by the random copolymer L-glutamic acid50-L-tyrosine50 (GT). 93 41

Synthetic polypeptides consisting of copolymers of glutamic acid and leucine have been shown to be useful materials for the fabrication of practical, biodegradable delivery vehicles for narcotic antagonists. Model delivery vehicles in film form were prepared from copolymers containing 10 mole percent to 40 mole percent glutamic acid, and loaded with 10% to 40% naltrexone by weight. The naltrexone was found to be released by diffusion, exhibiting diffusion coefficients that varied as a function of the glutamic acid content and the initial naltrexone loading. A wide range in diffusion coefficients were achieved (0.31 x 10-7 cm2/hr to 120 x 10-7 cm2/hr), leading to release rates within practical ranges of interest for meeting the program goals. We have demonstrated that the polypeptides can be fabricated into dosage forms that are amenable to administration by trochar. For example, rods 0.4 mm to 0.8 mm in diameter containing as much as 40% naltrexone by weight were extruded using a simple compression mold and die arrangement. An in vitro evaluation of the rods showed that antagonist is released by diffusion at a continuously decreasing rate, a behavior similar to that observed with the film devices that were, nonetheless, capable of blocking an AD80 challenge of morphene sulfate in mice for more than 30 days. One of the most promising delivery vehicles that we have developed to date consists of a polypeptide tube filled with a naltrexone/polypeptide core. Preliminary experiments have shown that these devices may be capable of administering high, constant rates of release for prolonged periods of time. Additional work, however, is required to develop techniques for the preparation of reproducible delivery vehicles.
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PMID:Use of synthetic polypeptides in the preparation of biodegradable delivery vehicles for narcotic antagonists. 96 33

1. The primary structure of a 4Fe-4S ferredoxin from Bacillus stearothermophilus was determined and shown to consist of a single polypeptide chain of 81 amino acid residues. The molecular weight of the holoprotein is about 9120. 2. There are only four cysteine residues in the molecule; three of these are located near the N-terminus as a Cys-X-X-Cys-X-X-Cys segment, and the fourth cysteine residue is followed by a proline and located in the C-terminal half. 3. The Fe-S chromophore in B. stearothermophilus ferredoxin was previously well characterized and was shown to consist of a single 4Fe-4S cluster. This ferredoxin sequence establishes for the first time the relative location of the four cysteine residues necessary to bind the 4Fe-4S cluster of a 4Fe ferredoxin, and is in agreement with the criteria for the relative positions of the cysteines proposed from X-ray-crystallographic studies on an 8Fe (two 4Fe-4S clusters) ferredoxin. 4. The sequence of B. stearothermophilus ferredoxin is homologous in many segments to that of other bacterial ferredoxins, the degree of homology being greater towards ferredoxins from Desulfovibrio gigas and photosynthetic bacteria than to Clostridial ferredoxins. 5. The presence of a relatively higher number of glutamic acid and lower number of cysteine residues in the molecule may explain the greater thermal stability and oxygen-insenstivity of this ferredoxin.
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PMID:Amino acid sequence of a four-iron-four-sulphur ferredoxin isolated from Bacillus stearothermophilus. 99 43

Rabbit placental lactogen, a polypeptide hormone functionally related to the growth hormone/prolactin family, was isolated from placenta by (NH4)2SO4 precipitation, gel filtration and ion-exchange chromatography on DEAE-and CM-cellulose. The hormone was purified to more than 90% homogeneity, as determined by end-group analysis. On disc gel electrophoresis at pH9.0 it migrates as a pair of closely spaced bands with mobilities of 0.489 (minor band) and 0.511 (major band), and its isoelectric point is 6.1. Its mol.wt. is 20600, as determined by sedimentation--equilibrium centrifugation, and 24200, as estimated by gel electrophoresis in sodium dodecyl sulphate. Its amino acid composition resembles that of rabbit growth hormone and rat prolactin, except for a lower glutamic acid and leucine content. Like the prolactins, rabbit placental lactogen has two tryptophan and six cysteine residues, and its N-terminus, valine, is identical with that for human placental lactogen. By radioimmunoassay, it does not cross-react with antisera to either rat growth hormone or rat prolactin; in addition, it does not cross-react with antisera to bovine placental lactogen by double immunodiffusion. The similarity of the biochemical characteristics of rabbit placental lactogen to the other non-primate placental lactogens lends further support to the hypothesis that these molecules occupy a more central position in the growth hormone/prolactin "tree" than do their primate counterparts.
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PMID:The purification and characterization of rabbit placental lactogen. 100 34

Previous studies have demonstrated an inverse relationship between the net electrical charge of immunogens and the antibodies they elicit. This correlation was found to be expressed at the cellular level. It has been shown that thymus-derived cells may recognize immunogens on the basis of their overall electrical charge. In this study, charged T-independent copolymers composed of tyrosine, glutamic acid, and lysine of the D configuration were prepared in order to find out whether this net charge phenomenon holds also for immunogens which do not require helper T cells for generation of immune response. Spleen cells were fractionated over negatively charged glass bead columns, and their immunocompetence was tested by transferring them into irradiated recipient mice which were immunized with the dinitrophenylated acidic or basic T-independent carrier. No differences in the responsiveness to the dinitrophenyl group on either carrier could be detected in recipients of unfractionated or fractionated cells on the charged columns. Similar results were obtained with the negatively charged T-independent branched polypeptide poly-(DTyr,DGlu)-poly(DPro)--poly(DLys). Filtration of spleen cells through glass bead columns did not affect the immune response potential of the recipient mice. In contrast, a significant reduction was observed in the frequency of positive responses in recipients of filtered cells, which were immunized with the negatively charged T-dependent poly(DTyr,DGlu)-poly(DPro)--poly(DLys). Thus, the inverse net charge phenomenon holds only for T-dependent antigens.
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PMID:Lack of inverse relationship between the net charge of T-independent immunogens and the responding spleen cells. 108 Nov 4

Using sucrose density centrifugation and gel filtration of a 105000 X g supernatant of Bacillus brevis two enzymic activities of glycyl-tRNA synthetase were separated. Enzyme catalyzing the aminoacylation of tRNA (E1) elutes in a high-molecular-weight region. Enzyme active in glycylhydroxamate formation (E2) elutes from a Sephadex gel column and sediments in sucrose density gradient in a region of relatively low molecular weight. The presence of two enzymic activities does not depend on the method of cell disruption; their proportion does not change when protease inhibitor (diisopropylphosphorofluoridate) is added to the extraction buffer. Both E1 and E2 were purified to a nearly homogeneous state. Sedimentation coefficients (sw,20) were found to be 8.6 S and 3.6 S and molecular weights 226000 and 66000 for E1 and E2, respectively. During storage, E1 dissociates into two components, one of which has electrophoretic mobility identical to E2. The molecular weight of the other component is about 1600000. Electrophoresis of E1 in the presence of sodium dodecylsulfate reveals two bands corresponding to molecular weights of 81000 and 30000. Under these conditions, E2 dissociates into a polypeptide with a molecular weight of 30000. Valine was found to be the N-terminal amino acid for E2 and both valine and glutamic acid were N-terminal amino acids for E1. It is concluded that E1 is a tetrameric protein consisting of two large and two small subunits (alpha2beta2). E2 is a component of E1 with a structural formula alpha2.
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PMID:Two enzymically active forms of glycyl-tRNA synthetase from Bacillus brevis. Purification and properties. 114 46

Thyroglobulin obtained from guinea pigs was examined by Na dodecyl-SO4-polyacrylamide gel electrophoresis after reduction and alkylation. In contrast to thyroglobulin from other mammalian sources, only three groups of polypeptide chains accounted for 95% or more of the protein. Determinations of the molecular weights of these purified proteins by equilibrium centrifugation in 6 M guanidine HCl gave values of 295,000 (species A), 210,000 (species B), and 110,000 (species C). Molecular weights determined by gel filtration in 6 M guanidine HCl gave similar results. Due to the large size of the polypeptides, satisfactory molecular weights could not be obtained from Na dodecyl-SO4-polyacrylamide gel electrophoresis. Amino acid analysis of the three species was similar to that of whole thyroglobulin. Only slightly higher level of lysine and histidine and a lower level of glutamic acid were seen in species C. The iodine contents were found to range from 0.07 to 0.12 to 0.20% for species A, B, and C, respectively.
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PMID:Elementary chain composition of guinea pig thyroglobulin. 116 42

Synthetic polypeptides consisting of copolymers of glutamic acid and leucine have been shown to be useful materials for the fabrication of practical, biodegradable delivery vehicles for narcotic antagonists. Model delivery vehicles in film form were prepared from copolymers containing 10 mole percent to 40 mole percent glutamic acid, and loaded with 10% to 40% naltrexone by weight. The naltrexone was found to be released by diffusion, exhibiting diffusion coefficients that varied as a function of the glutamic acid content and the initial naltrexone loading. A wide range in diffusion coefficients were achieved (0.31 x 10(-7) cm2/hr to 120 x 10(-7) cm2/hr), leading to release rates within practical ranges of interest for meeting the program goals. We have demonstrated that the polypeptides can be fabricated into dosage forms that are amenable to administration by trochar. For example, rods 0.4 mm to 0.8 mm in diameter containing as much as 40% naltrexone by weight were extruded using a simple compression mold and die arrangement. An in vitro evaluation of the rods showed that antagonist is released by diffusion at a continuously decreasing rate, a behavior similar to that observed with the film devices that were, nonetheless, capable of blocking an AD80 challenge of morphine sulfate in mice for more than 30 days. One of the most promising delivery vehicles that we have developed to date consists of a polypeptide tube filled with a naltrexone/polypeptide core. Preliminary experiments have shown that these devices may be capable of administering high, constant rates of release for prolonged periods of time. Additional work, however, is required to develop techniques for the preparation of reproducible delivery vehicles.
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PMID:Use of synthetic polypeptides in the preparation of biodegradable delivery vehicles for narcotic antagonists. 123 83


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