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1.
The cyanogen bromide peptide alpha 1(III)CB5 is 237 amino acid residues in length and occupies position 552--788 along the alpha 1(III) chain. For sequence analysis alpha 1(III)CB5 was fragmented with hydroxylamine, protease from Staphylococcus aureus V8, trypsin and the arginine-specific enzyme from mouse submaxillary gland. The peptides obtained were separated using molecular and ion exchange chromatography and sequenced with the automated Edman degradation procedure.  相似文献   

2.
The complete amino acid sequence of an extracellular guanyl-specific RNase from Aspergillus pallidus fungi has been established. The RNase contains 104 amino acid residues (Mr 11,029). Its primary structure was analyzed basing on the automated Edman degradation of the carboxymethylated RNase followed by tryptic digestion and sequencing of the resultant hydrolysate. An additional structural information was obtained by means of the automatic sequencing of the cyanogen bromide peptide mixture and by studying the kinetics of the RNase's digestion with carboxypeptidase Y.  相似文献   

3.
The cyanogen bromide peptide alpha 1-(III)CB1,8,10,2 is 180 amino acid residues in length and occupies position 223 to 402 along the alpha 1(III) chain. In order to elucidate its amino acid sequence, alpha 1(III)CB1,8,10,2 was fragmented with hydroxylamine, protease from Staphylococcus aureus V8 and trypsin. Peptides necessary for sequence analysis with the automated Edman degradation were separated using molecular and ion exchange chromatography. Edman degradation of the hydroxylamine-derived fragments resulted in the elucidation of 80% of the entire sequence. The rest was completely established by sequence analysis of some protease V8 and trypsin-derived peptides.  相似文献   

4.
The complete amino acid sequence of Penicillium chrysogenum 152A guanyl-specific RNase has been established using automated Edman degradation of two non-fractionated peptide mixtures produced by tryptic and staphylococcal protease digests of the protein. The RNase contains 102 amino acid residues: His2, Arg3, Asp7, Asn8, Thr5, Ser11, Glu4, Gln2, Pro4, Gly11, Ala13, Cys4, Val8, Ile3, Leu3, Tyr9, Phe5 (Mr 10 747).  相似文献   

5.
The amino acid sequence of rubber elongation factor, a recently discovered protein tightly bound to rubber particles isolated from the commercial rubber tree Hevea brasiliensis, is presented. The role of this protein in rubber elongation and its interaction with prenyltransferase and rubber particles have been discussed in the preceding paper in this series (Dennis, M. S., and Light, D. R. (1989) J. Biol. Chem. 264, 18608-18617). Trypsin, Staphylococcus protease, chymotrypsin, acetic acid, and hydroxylamine cleavage were used to generate peptide fragments that were isolated by reverse phase high pressure liquid chromatography and analyzed by amino acid composition and automated Edman degradation. Each digest contained one blocked peptide identified as the amino terminus. The blocked amino-terminal peptide from the tryptic digest was analyzed by amino acid composition, fast atom bombardment mass spectrometry (molecular ion 1659.9), subdigested with Staphylococcus protease for partial sequence analysis, and finally deblocked with bovine liver acyl-peptide hydrolase removing an acetylalanine to allow analysis by Edman degradation. Rubber elongation factor is 137 amino acids long, has a molecular mass of 14,600 daltons, and lacks four amino acids: cysteine, methionine, histidine, and tryptophan. The NH2 terminus is highly charged and contains only acidic residues (5 of the first 12 amino acids). The first four amino acids are highly represented in other known NH2-terminally acetylated proteins. Comparison of the sequence of rubber elongation factor with other known sequences does not reveal significant sequence similarities that would suggest an evolutionary relationship.  相似文献   

6.
Biopterin     
An enzyme that catalyzes the conversion of 2-amino-6-(5'-triphosphoribosyl)amino-5- or 6-formamido-6-hydroxypyrimidine, but not of guanosine triphosphate, to quinonoid 6-(D-erythro-1'-2'-3'-trihydroxypropyl)dihydropterin triphosphate and formic acid has been purified to homogeneity from some mammalian brain and liver. The enzyme of a single strand is a basic protein of 9177 daltons consisting of 68 amino acid residues--except the enzyme from rat brain, which has one additional aspartic acid as residue 7. The enzyme possesses three free SH groups and, in its most active form, 1 mol of phosphate per mole of enzyme. Peptides isolated after hydrolysis with trypsin, chymotrypsin, or weak acid were separated by thin-layer chromatography and sequenced manually by Edman degradation. The complete sequence of the molecule was established as follows: (formula: see text)  相似文献   

7.
Two forms of RNases (RNase ML and RNase MM) from Aspergillus saitoi which are base non-specific and adenylic acid preferential were separated from each other by DEAE-cellulose column chromatography. They are indistinguishable with respect to enzymatic properties such as base preferability, pH optimum, kinetic constants measured with 2',3'-cUMP and 2',3'-cCMP as substrates, and effects of ionic strength, physical properties such as heat stability, isoelectric point and circular dichroism spectra, amino acid composition and immunological property. They only differ in carbohydrate content. The apparent molecular weight determined by SDS-disc electrophoresis was 36,000 for RNase ML and 32,000 for RNase MM. Both RNases were reduced and carboxymethylated, and then digested with trypsin, separately. Glycopeptides were isolated from the both digests by gelfiltration and paper chromatography. The amino acid compositions of glycopeptides obtained from RNase ML (ML TS-IIC) and that obtained from RNase MM (MM TS-IIIC) were the same. The amino acid sequences of both glycopeptides determined by Edman degradation and carboxypeptidase digestion were also the same. The results indicated that RNase ML and RNase MM were the same protein having different sizes of carbohydrate chains at one site on the molecule.  相似文献   

8.
The nucleotide sequence of serA, the structural gene of Escherichia coli which codes for D-3-phosphoglycerate dehydrogenase, has been determined. The structural gene contains 1233 nucleotides which code for the 409 amino acids of the subunit of the tetrameric enzyme, as well as the initiator methionine, which is cleaved from the mature protein, and the termination codon. The majority of the primary structure of the enzyme has been confirmed by automated Edman degradation of peptide fragments produced by a variety of cleavage agents. Comparison of the amino acid sequence of phosphoglycerate dehydrogenase with other NAD-dependent oxidoreductases reveals less than 20% homology, although conservation of certain specific residues in the coenzyme binding domain appears to be evident.  相似文献   

9.
The complete amino acid sequence of hepatic microsomal epoxide hydrolase has been determined. The protein contains 455 amino acid residues in a single polypeptide chain and has Mr = 52,691. Peptides from selective chemical and proteolytic cleavages were isolated by a combination of gel filtration and high performance liquid chromatography and sequenced by automated Edman degradation. Overlapping peptide sequences were used to deduce the complete sequence. This is the first epoxide hydrolase and the third microsomal enzyme for which the complete sequence has been determined.  相似文献   

10.
The cyanogen bromide peptide alpha 1(III)CB9A is 139 amino acid residues in length and occupies positions 789--927 along the alpha 1(III) chain. Peptides necessary for the complete sequence analysis were obtained after fragmentation of alpha 1(III)CB9B with trypsin, protease from Staphylococcus aureus V8, hydroxylamine and chymotrypsin. They were separated mainly by chromatography on Sephadex G-50 and phosphocellulose and subsequently sequenced using the automated Edman degradation procedure.  相似文献   

11.
NADH-cytochrome b5 reductases purified from bovine erythrocytes and from bovine brain and liver microsomes solubilized with lysosomal protease were subjected to structural analysis by using HPLC mapping, amino acid analysis of the resulting peptides, and NH2-terminal sequence analysis of apoproteins. HPLC maps of the tryptic peptides derived from these enzymes were very similar to each other, and amino acid analysis of the HPLC-separated peptides indicated that the structures of these enzymes are identical except for the NH2-terminal region. The NH2-terminal sequence of the brain enzyme determined by automated Edman degradation was as follows: NH2-Phe-Gln-Arg-Ser-Thr-Pro-Ala-Ile-Thr-Leu-Glu-Asn-Pro-Asp- Ile-Lys-Tyr-Pro-Leu-Arg-Leu-Ile-Asp-Lys-Glu-Val-Ile- This sequence is identical to that of liver enzyme except that the liver enzyme started at the 3rd Arg or 4th Ser. The NH2-terminal amino acid residue of the soluble erythrocyte enzyme was not detected by automated Edman degradation. The sequence analysis of a tryptic peptide from the erythrocyte enzyme indicated that Leu is present before the NH2-terminal Phe of the brain enzyme. The recently reported sequence of the apparently identical protein (Ozols et al. (1985) J. Biol. Chem. 260, 11953-11961) differs in two amino acid assignments from our sequence.  相似文献   

12.
The complete amino acid sequence of lysozyme Ch has been established by a combination of automated and manual Edman degradation and carboxypeptidase digestion.(see article)There is a single disulfide bond in the center of the molecule. The enzyme has 211 residues with a calculated molecular weight of 22,415. Lysozyme Ch has an amino acid sequence that is totally different from all other lysozymes whose sequences are known.  相似文献   

13.
N5-(L-1-Carboxyethyl)-L-ornithine:NADP+ oxidoreductase (EC 1.5.1.-) from Streptococcus lactis K1 has been purified 8,000-fold to homogeneity. The NADPH-dependent enzyme mediates the reductive condensation between pyruvic acid and the delta- or epsilon-amino groups of L-ornithine and L-lysine to form N5-(L-1-carboxyethyl)-L-ornithine and N6-(L-1-carboxyethyl)-L-lysine, respectively. The five-step purification procedure involves ion-exchange (DE52 and phosphocellulose P-11), gel filtration (Ultrogel AcA 44), and affinity chromatography (2',5'-ADP-Sepharose 4B). Approximately 100-200 micrograms of purified enzyme of specific activity 40 units/mg were obtained from 60 g of cells, wet weight. Anionic polyacrylamide gel electrophoresis revealed a single enzymatically active protein band, whereas three species (pI 4.8-5.1) were detected by analytical electrofocusing. The purified enzyme is active over a broad pH range of 6.5-9.0 and is stable to heating at 50 degrees C for 10 min. Substrate Km values were determined to be: NADPH, 6.6 microM; pyruvate, 150 microM; ornithine, 3.3 mM; and lysine, 18.2 mM. The oxidoreductase has a relative molecular mass (Mr = 150,000) as estimated by high pressure liquid chromatography exclusion chromatography and by polyacrylamide gradient gel electrophoresis. Conventional gel filtration indicated an Mr = 78,000, and a single protein band of Mr = 38,000 was revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme is composed of identical subunits of Mr = 38,000, which may associate to yield both dimeric and tetrameric forms. Polyclonal antibody to the purified protein inhibited enzyme activity. The amino acid composition of the enzyme is reported, and the sequence of the first 37 amino acids from the NH2 terminus has been determined by stepwise Edman degradation.  相似文献   

14.
The complete amino acid sequence of acetyl-CoA carboxylase from chicken liver has been deduced by cloning and sequence analysis of DNA complementary to its messenger RNA. The results were confirmed by Edman degradation of peptide fragments obtained by digestion of the enzyme polypeptide with Achromobacter proteinase I or staphylococcal serine proteinase. Chicken liver acetyl-CoA carboxylase is predicted to be composed of 2,324 amino acid residues, having a calculated molecular weight of 262,706. The biotin carboxyl carrier protein domain is located in the middle region of the enzyme polypeptide. The amino-terminal portion of the acetyl-CoA carboxylase has been found to exhibit a homologous primary structure to that of carbamyl phosphate synthetase. Localization of possible functional domains including biotin carboxylase subsite in the acetyl-CoA carboxylase polypeptide is discussed.  相似文献   

15.
Riboflavin synthase was purified by a factor of about 1,500 from cell extract of Methanobacterium thermoautotrophicum. The enzyme had a specific activity of about 2,700 nmol mg(-1) h(-1) at 65 degrees C, which is relatively low compared to those of riboflavin synthases of eubacteria and yeast. Amino acid sequences obtained after proteolytic cleavage had no similarity with known riboflavin synthases. The gene coding for riboflavin synthase (designated ribC) was subsequently cloned by marker rescue with a ribC mutant of Escherichia coli. The ribC gene of M. thermoautotrophicum specifies a protein of 153 amino acid residues. The predicted amino acid sequence agrees with the information gleaned from Edman degradation of the isolated protein and shows 67% identity with the sequence predicted for the unannotated reading frame MJ1184 of Methanococcus jannaschii. The ribC gene is adjacent to a cluster of four genes with similarity to the genes cbiMNQO of Salmonella typhimurium, which form part of the cob operon (this operon contains most of the genes involved in the biosynthesis of vitamin B12). The amino acid sequence predicted by the ribC gene of M. thermoautotrophicum shows no similarity whatsoever to the sequences of riboflavin synthases of eubacteria and yeast. Most notably, the M. thermoautotrophicum protein does not show the internal sequence homology characteristic of eubacterial and yeast riboflavin synthases. The protein of M. thermoautotrophicum can be expressed efficiently in a recombinant E. coli strain. The specific activity of the purified, recombinant protein is 1,900 nmol mg(-1) h(-1) at 65 degrees C. In contrast to riboflavin synthases from eubacteria and fungi, the methanobacterial enzyme has an absolute requirement for magnesium ions. The 5' phosphate of 6,7-dimethyl-8-ribityllumazine does not act as a substrate. The findings suggest that riboflavin synthase has evolved independently in eubacteria and methanobacteria.  相似文献   

16.
The amino acid sequences of the major tryptic peptides from the coat protein of wild type cowpea chlorotic mottle virus are presented. The sequences have been determined by a combination of enzyme hydrolysis, mass spectrometry and Edman degradation, and the relative usefulness of mass spectrometry in this peptide sequence determination is discussed.  相似文献   

17.
The major secretory ribonuclease (RNase) of human urine (RNase HUA) was isolated and sequenced by automatic Edman degradation and analysis of peptides and glycopeptides. The isolated enzyme was shown to be free of other urine RNase activities by SDS/polyacrylamide-gel electrophoresis and activity staining. It is a glycoprotein 128 amino acids long, differing from human pancreatic RNase in the presence of an additional threonine residue at the C-terminus. It differs from the pancreatic enzyme in its glycosylation pattern as well, and contains about 45 sugar residues. Each of the three Asn-Xaa-Ser/Thr sequences (Asn-34, Asn-76, Asn-88) is glycosylated with a complex-type oligosaccharide chain. Glycosylation at Asn-88 has not been observed previously in mammalian secretory RNases. Preliminary sequence data on the major RNase of human seminal plasma have revealed no difference between it and the major urinary enzyme; their similarities include the presence of threonine at the C-terminus. The glycosylation pattern of human seminal RNase is very similar to that of the pancreatic enzyme. The structural differences between the secretory RNases from human pancreas, urine and seminal plasma must originate from organ-specific post-translational modifications of the one primary gene product. Detailed characterization of peptides and the results of gel filtration of tryptic and tryptic/chymotryptic digests of performic acid-oxidized RNase have been deposited as Supplementary Publication SUP 50146 (4 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1988) 249, 5.  相似文献   

18.
19.
Ribonuclease inhibitor from human placenta. Purification and properties   总被引:22,自引:0,他引:22  
A soluble ribonuclease inhibitor from the human placenta has been purified 4000-fold by a combination of ion exchange and affinity chromatography. The inhibitor has been isolated in 45% yield (about 2 mg/placenta) as a protein that is homogeneous by sodium dodecyl sulfate-gel electrophoresis. In common with the inhibitors of pancreatic ribonuclease from other tissues that have been studied earlier, the placental inhibitor is an acidic protein of molecular weight near 50,000; it forms a 1:1 complex with bovine pancreatic RNase A and is a noncompetitive inhibitor of the pancreatic enzyme, with a Ki of 3 X 10(-10) M. The amino acid composition of the protein has been determined. The protein contains 30 half-cystine plus cysteine residues determined as cysteic acid after performic acid oxidation. At pH 8.6 the nondenatured protein alkylated with iodoacetic acid in the presence of free thiol has 8 free sulfhydryl groups. The inhibitor is irreversibly inactivated by sulfhydryl reagents and also by removal of free thiol from solutions of the protein. Inactivation by sulfhydryl reagents causes the dissociation of the RNase - inhibitor complex into active RNase and inactive inhibitor.  相似文献   

20.
Dalcochinin-8'-O-beta-glucoside beta-glucosidase (dalcochinase) from the Thai rosewood (Dalbergia cochinchinensis Pierre) has aglycone specificity for isoflavonoids and can hydrolyze both beta-glucosides and beta-fucosides. To determine its structure and evolutionary lineage, the sequence of the enzyme was determined by peptide sequencing followed by PCR cloning. The cDNA included a reading frame coding for 547 amino acids including a 23 amino acid propeptide and a 524 amino acid mature protein. The sequences determined at peptide level were found in the cDNA sequence, indicating the sequence obtained was indeed the dalcochinase enzyme. The mature enzyme is 60% identical to the cyanogenic beta-glucosidase from white clover glycosyl hydrolase family 1, for which an X-ray crystal structure has been solved. Based on this homology, residues which may contribute to the different substrate specificities of the two enzymes were identified. Eight putative glycosylation sites were identified, and one was confirmed to be glycosylated by Edman degradation and mass spectrometry. The protein was expressed as a prepro-alpha-mating factor fusion in Pichia pastoris, and the activity of the secreted enzyme was characterized. The recombinant enzyme and the enzyme purified from seeds showed the same K(m) for pNP-glucoside and pNP-fucoside, had the same ratio of V(max) for these substrates, and similarly hydrolyzed the natural substrate, dalcochinin-8'-beta-glucoside.  相似文献   

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