Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.64 (proteinase K)
 4,071 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Aqualysin I is an alkaline serine protease which is secreted into the culture medium by Thermus aquaticus YT-1. Aqualysin I was purified, and its apparent relative molecular mass was determined to be 28 500. The enzyme contained four Cys residues (probably as two cystines), and its amino acids composition was similar to those of cysteine-containing serine proteases (proteinase K, etc.) as well as those of subtilisins. The NH2-terminal sequence of aqualysin I showed homology with those of the microbial serine proteases. The optimum pH for the proteolytic activity of aqualysin I was around 10.0. Ca2+ stabilized the enzyme to heat treatment, and the maximum proteolytic activity was observed at 80 degrees C. Aqualysin I was stable to denaturing reagents (7 M urea, 6 M guanidine.HCl and 1% SDS) at 23 degrees C for 24 h. The enzyme hydrolyzed the ester bond of an alanine ester and succinyl-Ala-Ala-Ala p-nitroanilide, a synthetic substrate for mammalian elastase. The cleavage sites for aqualysin I in oxidized insulin B chain were not specific when it was digested completely.
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PMID:Purification and characterization of aqualysin I (a thermophilic alkaline serine protease) produced by Thermus aquaticus YT-1. 316 11

Aqualysin I is an alkaline serine protease which is secreted into the culture medium by Thermus aquaticus YT-1, an extreme thermophile [Matsuzawa, H., Hamaoki, M. & Ohta, T. (1983) Agric. Biol. Chem. 47, 25-28]. The gene encoding aqualysin I was cloned into Escherichia coli using synthetic oligodeoxyribonucleotides as hybridization probes. The nucleotide sequence of the cloned DNA was determined. The primary structure of aqualysin I, deduced from the nucleotide sequence, agreed with the NH2-terminal sequence previously reported and the determined amino acid sequences, including the COOH-terminal sequence, of the tryptic peptides derived from aqualysin I. Aqualysin I comprised 281 amino acid residues and its molecular mass was determined to be 28,350. On alignment of the whole amino acid sequence, aqualysin I showed high sequence homology with the subtilisin-type serine proteases, and 43% identity with proteinase K, 37-39% with subtilisins and 34% with thermitase. Extremely high sequence identity was observed in the regions containing the active-site residues, corresponding to Asp32, His64 and Ser221 of subtilisin BPN'. The nucleotide sequence of the cloned DNA (1105 nucleotides) revealed that it contains the entire gene encoding aqualysin I and one open reading frame without a translational stop codon. Therefore, aqualysin I was considered to be produced as a large precursor, which contains a NH2-terminal portion, the protease and a COOH-terminal portion. The G + C content of the coding region for aqualysin I was 64.6%, which is lower than those of other Thermus genes (68-74%). The codon usage in the aqualysin I gene was rather random in comparison with that in other Thermus genes.
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PMID:Nucleotide sequence of the gene for aqualysin I (a thermophilic alkaline serine protease) of Thermus aquaticus YT-1 and characteristics of the deduced primary structure of the enzyme. 328 55

The PRB1 gene of Saccharomyces cerevisiae encodes the vacuolar endoprotease protease B. We have determined the DNA sequence of the PRB1 gene and the amino acid sequence of the amino terminus of mature protease B. The deduced amino acid sequence of this serine protease shares extensive homology with those of subtilisin, proteinase K, and related proteases. The open reading frame of PRB1 consists of 635 codons and, therefore, encodes a very large protein (molecular weight, greater than 69,000) relative to the observed size of mature protease B (molecular weight, 33,000). Examination of the gene sequence, the determined amino-terminal sequence, and empirical molecular weight determinations suggests that the preproenzyme must be processed at both amino and carboxy termini and that asparagine-linked glycosylation occurs at an unusual tripeptide acceptor sequence.
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PMID:Protease B of the lysosomelike vacuole of the yeast Saccharomyces cerevisiae is homologous to the subtilisin family of serine proteases. 332 23

A streptomycete isolated from cow manure produces an extracellular enzyme capable of lysing the pseudomurein-containing methanogen Methanobacterium formicicum. The lytic activity has been partially purified from culture fluid and appears to be a serine protease. Similar lytic activity has been fractionated from pronase. Optimal conditions have been developed for lysis of M. formicicum by commercial preparations of proteinase K. The three lytic enzymes have been partially characterized. The results with the three enzyme preparations tend to confirm that proteolytic enzymes are capable of lysing methanogen cells.
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PMID:Enzymatic lysis of the pseudomurein-containing methanogen Methanobacterium formicicum. 389 31

The three-dimensional structure of the fungal serine protease proteinase K has been determined at 3.3 A resolution by single crystal X-ray diffraction analysis. The enzyme crystallizes in the tetragonal space group P4(3)2(1)2 with cell constants a = b = 68.3 A, c = 108.5 A. The asymmetric unit consists of one monomer of 27 000 daltons mol. wt., approximately 50% higher than the so far assumed value of 18 500 daltons. The main chain fold of proteinase K shows a high degree of tertiary homology with the corresponding bacterial subtilisin BPN'. Proteinase K is the second enzyme in this family of serine proteases to be studied by X-ray diffraction, thus confirming the existence of two unrelated families of serine proteases in pro-and eukaryotes.
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PMID:Three-dimensional structure of fungal proteinase K reveals similarity to bacterial subtilisin. 637 21

The major extracellular proteases from the nematophagous fungus Verticillium chlamydosporium and the entomophagous fungus Metarhizium anisopliae, VCP1 and Pr1, respectively, are closely related both functionally and serologically. Antibodies raised against either enzyme cross-reacted with both antigens, suggesting that they have common epitopes. The VCP1 and Pr1 antisera labelled bovine pancreatic elastase and proteinase K, respectively. Neither antiserum reacted with commercial chymotrypsin. An antiserum to a serine protease from the closely related V. suchlasporium also cross-reacted with VCP1 and Pr1. In contrast, a polyclonal antibody to an isoform of Pr1 exclusive to M. anisopliae isolate ME1 failed to recognize Pr1 from M. anisopliae V245 or VCP1. The N-terminal amino acid sequence of VCP1 revealed similarities with subtilisin-like enzymes from other fungi, but the closest match was with Pr1. The pure enzymes, VCP1 and Pr1, failed to hydrolyse mono-aminoacyl-naphthylamide substrates but demonstrated dipeptidyl peptidase activity against Gly-Pro-beta NA and Leu-Ala-beta NA, respectively. These results are discussed in the context of specificity of invertebrate mycopathogens.
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PMID:The subtilisins of the invertebrate mycopathogens Verticillium chlamydosporium and Metarhizium anisopliae are serologically and functionally related. 772 66

Tegumental extracts from adult worms of Schistosoma mansoni contain an inhibitory activity to the S. mansoni 28-kDa serine protease and to pancreatic elastase. By using biotinylated elastase and streptavidin-agarose, the postulated protease inhibitor has been isolated from the crude worm extract in a single step. Monospecific rabbit antibodies raised against the protease inhibitor have immunoprecipitated a 56-kDa [35S]Met-labeled serine protease inhibitor which was designated Smpi56 (S. mansoni protease inhibitor, 56 kDa). Smpi56 binds tightly to and inhibits the 28-kDa protease of S. mansoni and pancreatic and neutrophil elastase but not papain, pepsin, thrombin, trypsin, chymotrypsin, proteinase K, urokinase and acetylcholinesterase. The biological function of Smpi56 is still not known, but in view of its elastase inhibitory activity it may be speculated that the parasite is employing Smpi56 to protect itself from activated neutrophils. Smpi56 may also potentially protect the parasite from its endogenous 28-kDa protease.
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PMID:Schistosoma mansoni: isolation and characterization of Smpi56, a novel serine protease inhibitor. 811 69

Transformation of cercariae of Schistosoma mansoni into schistosomula is accompanied by release of a soluble 28-kDa serine protease (s28) from the acetabular glands. The postulated activities of s28 include cleavage of skin connective tissue proteins (elastin, etc.), release of the cercarial glycocalyx, and cleavage of complement proteins. Our previous results demonstrated the presence of an antigenically cross-reactive protein on the surface of mechanically transformed schistosomula. As shown here, schistosomula express on their surface a 28-kDa serine protease (m28) which can be immunoprecipitated with anti-s28 antibodies. m28 eluted from the schistosomular tegumental membrane with NP-40 was purified to homogeneity in one step by adsorption on a chymotrypsin inhibitor column: 6-aminocaproyl-D-tryptophan methyl ester-Sepharose. Proteolytic activity of m28 was completely inhibited by the chymotrypsin inhibitor N-succinyl-Ala-Ala-Pro-Phe-chloromethyl ketone. Efficient removal of m28 from schistosomula was achieved with NP-40, deoxycholate, cholate, Tween 20, and phospholipases A2 and C, but not with papain, trypsin, pronase, or proteinase K. Furthermore, treatment with phosphatidyl inositol-specific phospholipase C (PI-PLC) followed by hydroxylamine also released m28. Anti-cross-reactive determinant antibodies which recognize a neo epitope exposed in glycosyl phosphatidyl inositol-containing molecules cleaved by PI-PLC bind to purified m28. The latter results suggest that m28 is anchored to the tegumental membrane of schistosomula by a lipid anchor and that perhaps some of the m28 molecules are bound via glycosylphosphatidyl inositol. Based on inhibitor sensitivity and antigenic cross-reactivity, it is conceivable that s28 and m28 are related, if not identical, proteins. Finally, m28 was detected antigenically also on lung-stage and adult worms of S. mansoni.
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PMID:Schistosoma mansoni: evidence for a 28-kDa membrane-anchored protease on schistosomula. 865 54

ORF 1a of lactate dehydrogenase-elevating virus, strain P (LDV-P), encodes a protein of 2206 amino acids. Eisenberg hydrophobic moment analysis of the protein predicted the presence of eleven transmembrane segments in the C-terminal half of the molecule (amino acids 980-1852) that flank the serine protease domain. cDNAs encoding ORF 1a protein segments encompassing transmembrane segments 5 to 11 and its amphipathic C-terminal end as well as the N-terminal 80 amino acids of the downstream ORF 1b protein were transcribed and the transcripts in vitro translated in the absence and presence of microsomal membranes. The synthesis of the protein products with putative transmembrane segments was enhanced by the presence of the microsomal membranes and the proteins became membrane associated. When synthesized in the absence of membranes they were recovered in the supernatant upon ultracentrifugation of the translation reaction mixtures, whereas they were recovered in the membrane pellet when synthesized in the presence of membranes. Furthermore, the latter proteins were not released from the membranes by disruption of the membrane vesicles in carbonate buffer, pH 11.5, and large portions of the proteins were resistant to digestion by trypsin, chymotrypsin and proteinase K. No N-glycosylation was observed and only little, if any, processing of the protein by the putative serine protease. The results indicate that the C-terminal half of the ORF 1a protein represents a non-glycosylated integral membrane protein. Potential modes of synthesis and function of the protein are discussed. In addition, the results showed that the synthesis of the ORF 1a protein was generally terminated at its termination codon, but that read-through into the ORF 1b gene occurred with low frequency.
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PMID:Membrane association of the C-terminal half of the open reading frame 1a protein of lactate dehydrogenase-elevating virus. 877 92

We studied the role of proteases in apoptosis using a cell-free system prepared from a human leukemia cell line. HL60 cells are p53 null and extremely sensitive to a variety of apoptotic stimuli including DNA damage induced by the topoisomerase I inhibitor, camptothecin. We measured DNA fragmentation induced in isolated nuclei by cytosolic extracts using a filter elution assay. Cytosol from camptothecin-treated HL60 cells induced internucleosomal DNA fragmentation in nuclei from untreated cells. This fragmentation was suppressed by serine protease inhibitors. Serine proteases (trypsin, endoproteinase Glu-C, chymotrypsin A, and proteinase K) and papain by themselves induced DNA fragmentation in naive nuclei. This effect was enhanced in the presence of cytosol from untreated cells. Cysteine protease inhibitors (E-64, leupeptin, Ac-YVAD-CHO [ICE inhibitor]) did not affect camptothecin-induced DNA fragmentation. The apopain/Yama inhibitor, Ac-DEVD-CHO, and the proteasome inhibitor, MG-132, were also inactive both in the cell-free system and in whole cells. Interleukin-1 beta converting enzyme (ICE) or human immunodeficiency virus protease failed to induce DNA fragmentation in naive nuclei. Together, these results suggest that DNA damage activates serine protease(s) which in turn activate(s) nuclear endonuclease(s) during apoptosis in HL60 cells.
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PMID:DNA fragmentation induced by protease activation in p53-null human leukemia HL60 cells undergoing apoptosis following treatment with the topoisomerase I inhibitor camptothecin: cell-free system studies. 880 33


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