Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The amide content of neocarzinostatin (NCS), an antitumor protein, has been determined by analysing asparagine and glutamine in the Pronase-aminopeptidase M digests of tetra-S-carboxymethyl-NCS and carboxyl-modified NCS (modified with a water-soluble carbodiimide and [14C]glycine methyl ester). Preneocarzinostatin (PRE) was separated and purified from a crude NCS preparation by CM-cellulose column chromatography. PRE was found to contain one mole less asparagine than NCS, and asparagine was deamidated to aspartic acid in PRE. A time-dependent conversion of NCS to PRE at pH 3.2 at 4 degrees or in 0.1 M acetic acid at 26 degrees was studied in two ways; first, by quantitative determination of NCS and PRE by CM-cellulose column chromatography and second, by following the release of free NH3 during dialysis in an air-tight container. Within experimental error, PRE was indistinguishable from NCS in amino acid content after acid hydrolysis, as well as in apparent molecular weight as determined by SDS-disc gel electrophoresis (10% acrylamide), and N- and C-terminal amino acid residues. Both NCS and PRE shared a common antigenicity as determined by Ouchterlony's agar diffusion method. Only a slight difference between the two in electrophoresis on a cellulose acetate membrane and on a peptide map of the tryptic digest was demonstrated. PRE, however, was completely devoid of biological activity. In addition to the chromatographic difference, a conformational difference was observed by CD spectroscopy, namely, an apparently looser structure of PRE was indicated by the shallowness of the trough in the 240-265 nm region. This interpretation was supported by the finding that digestions by Pronase were more extensive with PRE than with NCS. These results indicate an important role of the single asparagine residue (Asn 83) of NCS in the biological activity, which is evidently governed by the conformation.
 ...
PMID:Spontaneous deamidation of a protein antibiotic, neocarzinostatin, at weakly acidic pH. Conversion to a homologous inactive preneocarzinostatin due to change of asparagine 83 to aspartic acid 83 accompanied by conformational and biological alterations. 1 34

By a mild alkaline treatment of pyocin R1, the core particle was released from the contracted sheath. After sucrose density-gradient centrifugation, core-rich fractions were treated with anti-sheath serum and by a second density-gradient centrifugation, purified core particles were isolated. Homogeneity of the preparation was confirmed by observation under the electron microscope, immuno-precipitation reaction, and sucrose density-gradient centrifugation. The core particle exhibited a sedimentation coefficient of 37S. The quaternary structure of the core consists of a single kind of subunit protein with a molecular weight of 18,000. No contamination by other proteins was detected by SDS-disc electrophoreses. Amino acid analysis revealed that the core is rich in glycine, alanine, valine, leucine, aspartic acid (or asparagine), glutamic acid (or glutamine), and serine. This amino acid composition bears some resemblance to that of T-even bacteriophage tail-core.
 ...
PMID:Isolation, homogeneity, and properties of core particle from pyocin R1. 10 48

Dialdehyde starch (DAS) reacts unspecifically with the amino acid residues of the 11 S globulin from sunflower seed. The modification of the protein causes a decrease of the content of each amino acid. Their blocking reaches maximum values at high pH levels (9,5) and high concentration of protein (5%). Especially high reactivity is shown by arginine as well as by the hydrophobic amino acids isoleucine, valine, and proline, and furthermore by histidine, lysine, asparagine (aspartic acid), and glutamine (glutamic acid). By reaction with DAS at pH 8.0 70% of the amino groups are blocked within 6 h; on the contrary, glyoxale blocks only 30% of the amino groups. Owing to the blockage of charged amino acid groups, a shift of the isoelectric point of the protein to a lower pH (4,3-4,4) takes place; this effect can be followed for 2 days. As a result of the reaction with DAS, only small amounts (10-15%) of intermolecular crosslinkage products with sedimentation coefficients of 17 S and greater than 17 S were formed. But by means of SDS-gel electrophoresis, dimers and trimers of the polypeptide chains in the protein were detected.
 ...
PMID:[Chemical modification of proteins. 5. Modification of the 11-S-globulin from sunflower seed by reaction with dialdehyde starch]. 47 Oct 38

PP10 was isolated from aqueous extracts of human term placentae by fractionating the proteins with rivanol and ammonium sulfate, by gelfiltration on Sephadex G-150 and by use of immunoadsorbents. PP10 apparently is a protein specific for the placenta; it could not be detected in extracts from other human tissues. From one human term placenta an average amount of 20 mg PP10 can be extracted. In sera from pregnant women PP10 is usually present only in trace amounts (less than 0.1 mg/100 ml). PP10 has the electrophoretic mobility of an alpha1-globulin and an isoelectric point of 5.1. The purified protein sediments with 3.8 S. PP10 was found to have a molecular weight of 48,000 as determined by ultracentrifugation and a molecular weight of 65,000 as determined by SDS-PAA gel electrophoresis. PP10 is a glycoprotein containing 6.65% carbohydrates (hexoses 4.8%, hexosamines 1.2%, fucose 0.05%, sialic acid 0.6%). The amino acid composition of PP10 has been determined, too; the most abundant amino acids in this protein are glutamic acid, aspartic acid, leucine and alanine.
 ...
PMID:[Isolation and characterization of a new placenta specific protein (PP10) (author's transl)]. 48 20

A simple and effective method to purify a phosphoprotein (B2) (Mr 68,000, pI 6.2-8) from phenol-soluble non-histone chromatin proteins of rat liver is described. The purification involved only two steps, CM-cellulose chromatography and preparative SDS/polyacrylamide (10%)-gel electrophoresis. The purified phosphoprotein B2 was shown to be homogeneous by SDS/polyacrylamide-gel electrophoresis. The yield was 2% of total non-histone chromatin proteins. The acidic to basic amino acid ratio of phosphoprotein B2 was less than 1, with high contents of glutamic acid, aspartic acid, arginine, lysine, glycine and alanine. The phosphate content of this protein is 0.3%.
 ...
PMID:Purification of a phosphoprotein from chromatin of rat liver. 53 78

Ten different group A streptococcal M-protein preparations purified by trichloroacetic acid precipitation and three M-protein preparations purified by cellulose chromatography were examined by SDS and polyacrylamide gel electrophoresis, and analyzed for amino acid composition and N-terminal amino acids. Fingerprinting (both tryptic and chymotryptic) was performed on the cellulose purified preparations of M1, M12, and M29 proteins which showed these proteins to be structurally related. Trypsin produced mas with 37 to 42 peptides, whereas chymotrypsin digestion resulted in 8 to 12 peptides, depending on the M-type. Sequencing was performed on the M12 protein and tentative identification of nine N-terminal amino acids made. Molecular weights of the cellulose and TCA-purified M-proteins were determined by SDS gel electrophoresis and chromatography on G-200 Sephadex, with comparable results, indicating followed the patterns established for M-proteins, with high concentrations of lysine, aspartic acid, glutamic acid, alanine, and leucine. All 10 proteins had L-alanine as their N-terminal amino acid. Evidence for a one way cross-reaction between type 1 and type 29 streptococci was also found.
 ...
PMID:Characterization of group A streptococcal M-proteins purified by two methods. 96 21

The E7 open reading frames of human papillomavirus type 6 (HPV-6) and HPV-16 encode proteins consisting of 98 amino acids that are quite similar in sequence yet different in electrophoretic mobility. Moreover, these proteins vary strikingly in oncogenicity. To investigate the molecular basis of the differences in structure and function, site-directed mutagenesis was used to exchange non-conserved amino acid residues between the two proteins. The mutated coding regions were expressed as fusion proteins in Escherichia coli and identified by Western blotting. Comparative analysis of the affinity-purified mutated E7 fusion proteins in polyacrylamide slab mini-gels in the presence of SDS and 2-mercaptoethanol revealed altered electrophoretic mobilities. This analysis suggests that the aspartic acid at residue 4 (Asp 4) contributes to the characteristic aberrant migration of the HPV-16 E7 protein in SDS-polyacrylamide gels.
 ...
PMID:Mutagenesis of human papillomavirus types 6 and 16 E7 open reading frames alters the electrophoretic mobility of the expressed proteins. 131 45

To understand more directly the tissue defect in osteogenesis imperfecta (OI), bone matrix was analyzed from an infant with lethal OI (type II) of defined mutation (collagen alpha 2(I)Gly580-->Asp). Pepsin-solubilized alpha 1(I) and alpha 2(I) chains and derived CNBr-peptides migrated more slowly on sodium dodecyl sulfate-polyacrylamide gel electrophoresis compared with normal human controls. The peptide alpha 2(I)CB3,5, predicted to contain the mutation site, ran as a retarded doublet band and was purified by high performance liquid chromatography and digested with V8 protease. Two peptides with amino-terminal sequences beginning at residue 576 of the alpha 2(I) chain were isolated. One had the normal sequence. The other differed in that aspartic acid replaced glycine at residue 580 as predicted from cDNA analysis, and in having an unhydroxylated proline at residue 579. From yields on microsequencing and the relative intensities of the two forms of alpha 2(I)CB3,5 on SDS-polyacrylamide gel electrophoresis, the ratio of mutant to normal alpha 2(I) chains in the infant's bone matrix was 0.7/1. Although the effects of an efficient incorporation of mutant chains on the properties of the bone matrix are unknown, it may be that in this OI case the tissue abnormalities result more from the presence of mutant protein than from an underexpression of matrix.
 ...
PMID:Incorporation of type I collagen molecules that contain a mutant alpha 2(I) chain (Gly580-->Asp) into bone matrix in a lethal case of osteogenesis imperfecta. 138 13

A glutamic acid-specific protease has been purified to homogeneity from Bacillus licheniformis ATCC 14580 utilizing Phe-Leu-D-Glu-OMe-Sepharose affinity chromatography and crystallized. The molecular weight of the protease was estimated to be approximately 25,000 by SDS-polyacrylamide gel electrophoresis. This protease, which we propose to call BLase (glutamic acid-specific protease from B. licheniformis ATCC 14580), was characterized enzymatically. Using human parathyroid hormone (13-34) and p-nitroanilides of peptidyl glutamic acid and aspartic acid, we found a marked difference between BLase and V8 protease, EC 3.4.21.9, although both proteases showed higher reactivity for glutamyl bonds than for aspartyl bonds. Diisopropyl fluorophosphate and benzyloxycarbonyl Leu-Glu chloromethyl ketone completely inhibited BLase, whereas EDTA reversibly inactivated the enzyme. The findings clearly indicate that BLase can be classified as a serine protease. To elucidate the complete primary structure and precursor of BLase, its gene was cloned from the genomic DNA of B. licheniformis ATCC 14580, and the nucleotide sequence was determined. Taking the amino-terminal amino acid sequence of the purified BLase into consideration, the clones encode a mature peptide of 222 amino acids, which follows a prepropeptide of 94 residues. The recombinant BLase was expressed in Bacillus subtilis and purified to homogeneity. Its key physical and chemical characteristics were the same as those of the wild-type enzyme. BLase was confirmed to be a protease specific for glutamic acid, and the primary structure deduced from the cDNA sequence was found to be identical with that of a glutamic acid-specific endopeptidase isolated from Alcalase (Svendsen, I., and Breddam, K. (1992) Eur. J. Biochem. 204, 165-171), being different from V8 protease and the Glu-specific protease of Streptomyces griseus which consist of 268 and 188 amino acids, respectively.
 ...
PMID:Purification, characterization, cloning, and expression of a glutamic acid-specific protease from Bacillus licheniformis ATCC 14580. 142 18

Mature (average patient age = 29.5 yr, closed apical foramen) and immature (average patient age = 17.5 yr, open apical foramen) root shards were placed in dialysis tubing and demineralized to completion using either 10% disodium EDTA plus protease inhibitors or 0.6 N HCl. The demineralized shards were re-extracted (five times) with 0.05 M tris-HCl, 1.0 M NaCl and then collagenase digested. No major differences were observed in chromatograms of extracts, re-extracts or collagenase digests from root shards demineralized in either way. In contrast, chromatograms of immature and mature roots showed qualitative differences. Chromatograms of mature roots demineralized in either way showed broader protein peaks and less organic phosphorus than those from immature tooth roots. A distinct band amid degraded phosphoprotein (150 K) was found in SDS-PAGE gels (7.5%) from EDTA-extracted immature tooth roots but not from mature tooth roots. Electroelution of this band revealed a typical phosphoprotein amino-acid profile containing increased aspartic acid and serine residues. Comparison of the total phosphoprotein and amino acid composition of extracts, re-extracts and collagenase digests revealed that phosphoprotein, serine and to a lesser extent aspartic acid were recovered in greater quantities from immature roots than mature tooth roots. These data suggest that the degree of maturation is crucial to the isolation of an intact phosphoprotein and provides additional evidence that human dentine phosphoprotein undergoes amino acid compositional changes during maturation.
 ...
PMID:Comparison of phosphoprotein isolated from mature and immature human tooth roots. 147 54


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