Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.27 (thermolysin)
 1,894 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of various chemical and enzymatic treatments on the biological activity of porcine luteinizing hormone-releasing hormone (LH-RH) are described. This experiment was performed before the elucidation of the structure of LH-RH. LH-RH activity was abolished by the following endopeptidases: chymotrypsin, subtilisin, papain, and thermolysin, but not by pepsin or trypsin. Exopeptidases did not affect LH-RH activity, but a purified preparation of pyrolidone carbosylpeptidase did. The amino acid sequence of LH-RH/FSH-RH was established to be (pyro)Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-Amine. This decapeptide lacks both the Amine terminus and the COOH terminus. Its Amine-terminal dipeptide sequence,(pyro)Glu-His, is similar to that of tyrotropin-releasing hormone. The lack of inactivation by the exopeptidases is in good agreement with these findings. Treatment with various chemical reagents showed that tyrosine, histidine, tryptophan, and arginine in LH-RH are important for its biological activity. Nitrous acid and Edman degradation did not inactivate LH-RH. These results are also in agreement with the determined structure of LH-RH. This hormone showed a high follicle-stimulating hormone-releasing hormone (FSH-RH) activity. The inactivation of LH-RH was always accompanied by a loss of FSH-RH activity. These experiments also shed some light on the structure-activity relationship of this hormone.
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PMID:Studies on the properties of hypothalamic luteinizing hormone-releasing hormone. 494 14

Cyanogen bromide (CB) cleavage of Neurospora tyrosinase resulted in four major fragments, CB1 (222 residues), CB2 (82 residues), CB3 (68 residues), and CB4 (35 residues), and one minor overlap peptide CB2-4 (117 residues) due to incomplete cleavage of a methionylthreonyl bond. The sum of the amino acid residues of the four major fragments matches the total number of amino acid residues of the native protein. The amino acid sequences of the cyanogen bromide fragments CB2, CB3, and CB4 were determined by a combination of automated and manual sequence analysis on peptides derived by chemical and enzymatic cleavage of the intact and the maleylated derivatives. The peptides were the products of cleavage by mild acid hydrolysis, trypsin, pepsin, chymotrypsin, thermolysin, and Staphylococcus aureus protease V8. The cyanogen bromide fragment CB1 was found to contain two unusual amino acids whose chemical structure will be presented in the following paper.
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PMID:Primary structure of tyrosinase from Neurospora crassa. I. Purification and amino acid sequence of the cyanogen bromide fragments. 621 Jun 95

In addition to trypsin, eight other proteolytic enzyme preparations were tested for their ability to assist simian rotavirus SA-11 plaque formation in MA-104 cells. When incorporated in the overlay (minimal essential medium and 0.7% Ionagar No. 2) in the concentrations per mL indicated, alpha-chymotrypsin (10 micrograms), elastase (0.5 micrograms), subtilisin (0.5 micrograms), pronase (2.5 micrograms) and pancreatin (25 micrograms) were as efficient as trypsin (5 micrograms) in helping SA-11 produce 3-4 mm diameter plaques after five days of incubation at 37 degrees C. No plaques were produced when pepsin (25 micrograms), papain (10 micrograms) or thermolysin (10 micrograms) was added to the overlay. Addition of soybean trypsin inhibitor to alpha-chymotrypsin-, pronase- or pancreatin-containing overlays completely inhibited virus plaque production. A similar effect was not seen with elastase or subtilisin.
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PMID:Proteolytic enzymes and rotavirus SA-11 plaque formation. 625 Jun 85

The 350-residue amino acid sequence of the catalytic subunit of bovine cardiac muscle adenosine cyclic 3',5'-phosphate dependent protein kinase is described. The protein has a molecular weight of 40 862, which includes an N-tetradecanoyl (myristyl) group blocking the NH2 terminus and phosphate groups at threonine-197 and serine-338. Seven methionyl bonds in the S-carboxymethylated protein were cleaved with cyanogen bromide to yield eight primary peptides. These fragments, and subpeptides generated by cleavage with trypsin, pepsin, chymotrypsin, thermolysin, and Myxobacter AL-1 protease II, were purified and analyzed to yield the majority of the sequence. The primary peptides were aligned by analyses of overlapping peptides, particularly of methione-containing tryptic peptides generated after in vitro [14C]methyl exchange labeling of methionyl residues in the intact protein.
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PMID:Amino acid sequence of the catalytic subunit of bovine type II adenosine cyclic 3',5'-phosphate dependent protein kinase. 631 Dec 52

The complete primary structure of turkey muscle acylphosphatase has been determined. The sequence was derived from peptides obtained by digestion of the carboxymethylated protein with pepsin and thermolysin and by subdigestion of some of the cyanogen bromide fragments with trypsin and Staphylococcus aureus protease. Peptides were purified by preparative finger prints and/or preparative high-performance liquid chromatography. Sequencing of the various peptides was achieved by manual Edman degradation and by time-course analysis of amino acids released by carboxypeptidases. The amino-terminal blocking group (acetyl) was determined by fast atom bombardment mass spectrometry. This sequence was compared with that of horse muscle enzyme determined previously.
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PMID:The primary structure of turkey muscle acylphosphatase. 631 87

Homogenates of hatching gland explants were fractionated by means of different electrophoretic techniques, and the fractions analyzed for proteolytic activity and for their capacity to affect the envelope of the eggs. Agar gel electrophoresis resulted in two fractions that were able to digest the zona radiata interna, and a third fraction that caused a significant swelling of the egg envelope. All three fractions were proteolytically active. Agarose gel and polyacrylamide gel electrophoresis gave only two fractions that showed proteolytic activity and were capable of digesting the zona radiata interna. The presence of these two fractions may imply that hatching enzyme is stored as proenzyme in the hatching gland granules. Swelling of egg envelopes was also observed during envelope digestion by thermolysin, pronase, and 0.5-1.0 N NaOH. Moreover, breakdown by hatching enzyme and pepsin under suboptimal conditions showed a slight swelling of the envelope. These results demonstrate that substances capable of solubilizing the zona radiata interna may cause envelope swelling. The swelling of the envelopes probably represents an intermediate phase in the proteolysis of the zona radiata interna. The agar gel electrophoresis fraction of hatching gland homogenates that causes swelling may contain a physicochemically different form of hatching enzyme.
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PMID:Hatching in the teleost Oryzias latipes: limited proteolysis causes egg envelope swelling. 634 51

A technique is described to detect the activity of protease inhibitors present in sodium dodecyl sulfate (SDS)-polyacrylamide gels (PAG) containing a copolymerized enzyme substrate. The method involved (1) incorporation of substrate (gelatin or casein) into the SDS-PAG at the time of casting; (2) electrophoresis of the protease inhibitors in the presence of SDS; (3) removal of SDS by washing the gel in 2.5% (w/v) Triton X-100; (4) incubation of the gels in a solution containing the proteolytic enzyme at 37 degrees C for 16 h; and (5) staining undigested substrate with amido black. Standard inhibitors such as bovine pancreatic trypsin inhibitor (BPTI), soybean trypsin inhibitor (SBTI), alpha 1-antitrypsin inhibitor, and a protease inhibitor derived from human articular cartilage have been examined by this method and displayed sharp inhibition bands when the gels were treated with bovine trypsin, chymotrypsin, or other enzymes. The technique cannot be used for precise quantification of protease inhibitors. However, there is a relationship between the concentration of inhibitor used and the intensity of staining. By this means, it was possible to estimate the smallest amount of inhibitor that could be detected (against a particular enzyme) under a given set of conditions. Inhibition was detected when 10 ng of SBTI or 20 ng of BPTI were applied to the gels; human alpha 1-protease inhibitor could be detected at a level of 2-3 micrograms. The technique was used to investigate the effectiveness of the human cartilage inhibitor against a variety of proteolytic enzymes, including thermolysin, Pronase, neutral protease, elastase, protease VII, pepsin, bacterial collagenase, protease IV, and papain.
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PMID:Detection of protease inhibitors using substrate-containing sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 635 99

A polypeptide proteinase inhibitor from human articular cartilage has been purified to homogeneity by stepwise Sephadex G-75, heparin-Sepharose and octyl-Sepharose affinity chromatography. The inhibitor is strongly cationic (pI greater than or equal to 10.5) and consists of two non-identical polypeptides associated by means of electrostatic and/or hydrophobic interactions. Amino acid analysis of the aggregate confirmed that the polypeptide was rich in basic, and hydrophobic amino acids and contained only one disulphide bridge. Sedimentation equilibrium studies showed that the aggregate had MW congruent to 7000 which could be dissociated into two polypeptides each of MW congruent to 3500. While the subunits were primarily serine proteinase inhibitors the aggregate form could also inhibit bacterial collagenase and pepsin but not thermolysin nor the cysteine proteinases, ficin or bromelain. Binding of 125I-labelled human cartilage inhibitor to heparin, keratan sulphate and proteoglycan subunit was demonstrated using gel exclusion chromatography but no interaction was detected with chondroitin 6-sulphate or hyaluronic acid. Binding of cartilage inhibitor subunits to link proteins was also shown by polyacrylamide electrophoresis. These data suggest that the human cartilage inhibitor may be localised at specific sites on the proteoglycan complex where it would be ideally placed to attenuate degradation by matrix proteinases or constitute part of an enzyme-inhibitor complex.
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PMID:Polypeptide proteinase inhibitor from human articular cartilage. 638 79

A protein capable of inhibiting trypsin and other pancreatic proteases has been purified to homogeneity from Escherichia coli by conventional procedures and affinity chromatography. It is stable for at least 30 min at 100 degrees C and pH 1.0, but it is inactivated by digestion with pepsin. The inhibitor has an apparent molecular weight of 38,000 as determined by gel filtration and must be a homodimer since it contains a single 18,000-dalton subunit upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The inhibitor has an isoelectric point of 6.1. One dimeric molecule of the inhibitor can bind two trypsin molecules to form a mixed tetrameric complex, in which trypsin molecules are completely inhibited. The inhibitor is not digested by the trypsin. When N-benzoyl-DL-arginine-p-nitroanilide was used as a trypsin substrate, half-maximal inhibition was observed at 22 nM. This protein also inhibits chymotrypsin, pancreatic elastase, rat mast cell chymase, and human serosal urokinase, but it does not inhibit human pulmonary tryptase, kallikrein, papain, pepsin, Staphylococcus aureus V8 protease, subtilisin, and thermolysin. Surprisingly, it did not inhibit any of the eight soluble endoproteases recently isolated from E. coli (i.e. proteases Do, Re, Mi, Fa, So, La, Ci, and Pi) nor the chymotrypsin-like (protease I) and trypsin-like (protease II) esterases in E. coli. The inhibitor is localized to the periplasmic space and its level did not change with different growth media or stages of cell growth. The physiological function of this E. coli trypsin inhibitor is unknown. We suggest that E. coli trypsin inhibitor be named "Ecotin."
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PMID:Purification from Escherichia coli of a periplasmic protein that is a potent inhibitor of pancreatic proteases. 641 24

The complete primary structure of Bacillus subtilis acidic protein B-L9, functionally equivalent to protein L7/L12 from E. coli, has been determined. B-L9 is composed of 122 residues and has the amino acid composition: Asp3, ASN3, Thr4, Ser3, Glu22, Gln1, Pro3, Gly11, Ala21, Val14, Ile9, Leu12, Phe2, Lys13, and Arg1. The molecular weight of B-L9 is 12,633. The amino acid sequence was determined by a combination of automated Edman degradation of the intact protein in a modified Beckman sequenator, and micro dansyl-Edman degradation of the peptides obtained from digestions with trypsin, thermolysin, Staphylococcus aureus protease, chymotrypsin and pepsin. A comparison of protein B-L9 from B. subtilis with E-L12 from E. coli shows a relatively high degree of homology.
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PMID:The primary structure of Bacillus subtilis acidic ribonsomal protein B-19. Isolation and characterization of peptides and the complete amino acid sequence. 677 Dec 49


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