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)

Some proteases, i.e. trypsin, alpha-chymotrypsin, thermolysin, proteinase K, alpha-amylase, collagenase, and papain were investigated on their effect on isolated zonular fibers. All these enzymes but collagenase were zonulolytic active. An attack on the ground substance of the fibers by substances solving glycosaminoglycans and proteoglycans (hyaluronidase, EDTA, guanidinium chloride, H2O2) showed an increased effect of the enzymes used. These results suggest that the interfibrillar matrix has a protective function on the zonular fibers.
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PMID:[The attack of different proteases on isolated zonular fibers (author's transl)]. 13 75

Four natural protease inhibitors have been partially purified by heat treatment, ion-exchange chromatography pand gel filtration from Neurospora crassa. The inhibitory activity has been estimated by measuring the inhibition of proteolysis of casein as well as by the protection of Neurospora tryptophan synthase from proteolytic inactivation. The inhibitors are all oligopeptides and possess molecular weights in the range 5000-24 000 and appear to be very specific to Neurospora proteases. They may be classified into two types. The first are specific to Neurospora alkaline protease and the second to acidic protease. None of them exhibited any effect on other proteases including trypsin, chymotrypsin, papain, pepsin, thermolysin, subtilisin and proteinase K. The possible physiological role of these inhibitors is discussed.
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PMID:Isolation of specific protease inhibitors from Neurospora crassa. 13 53

A method for the rapid manual isolation of polytene chromosomes and nuclear membranes from salivary glands of Chironomus tentans is presented and the analysis of some of their RNA and protein components before and after treatment with 2 M salt solutions is summarized.--After salt-incubation the chromosomes still display a considerable number of bands which stain with ethidium bromide and which are sensitive to treatment with DNase, RNase, trypsin, and proteinase K, to a lesser extent with pronase and papain. Analysis of the iodinated residual proteins on SDS gels yield three major and two minor bands (MW between 50,000 and 70,000 dalton) which were also shown to be present in interphase chromosomes of Ehrlich ascites cells which had been treated similarly and are also tightly bound constituents of DNA prepared according to Gross-Bellard et al. (1973). This result indicates the existence of a general class of non-histone proteins involved in keeping the DNA in a supercoiled state. Furthermore their presence in salt-treated nuclear membranes of Chironomus salivary gland cells (and Xenopus oocytes, unpubl.) will be of interest with respect to functional aspects of the nuclear matrix.
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PMID:Effect of salt-treatment on manually isolated polytene chromosomes from Chironomus tentans. 35 13

Protoplasts were isolated from cells of Acetabularia cliftonii, which are presumed to be haploid. The release of the protoplasts occurred after treatment of the cells with papain or proteinase K. They are genuine protoplasts since they contain a nucleus. Fusion was initiated by mechanically pushing together two protoplasts. Under these conditions, the efficiency of fusion was more than 90% within 30 minutes at room temperature. Haploid cells from one cyst, i.e., cells which eventually would have formed gametes of the same mating type, exhibit a greater propensity for fusion as compared to haploid cells from different cysts.
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PMID:Protoplasts from Acetabularia: isolation and fusion. 64 93

Using partial proteolytic cleavage, the nerve growth factor (NGF) binding site and the epitopes for two anti-NGF receptor (NGFR) monoclonal antibodies were localized on the recombinant extracellular domain (RED) of the NGFR. The RED was prepared in the baculovirus-insect cell system and was purified by immunoaffinity and ion-exchange chromatography. The four cysteine-rich repeat domains and some additional C-terminal sequences were resistant to proteolysis with papain or proteinase K. The Mr 32,000 papain-resistant fragment (P32) and the Mr 30,000 proteinase K-resistant fragment (K30) share the same N terminus as the intact RED and have C termini in the vicinity of residue 170. Even though P32 and K30 have the same N terminus and probably differ by only a small number of amino acids at the C terminus, P32, but not K30, binds 125I-NGF. As judged by Western blot analysis, two anti-NGFR antibodies (ME20.4 and NGFR5) bind to P32 but have a lesser affinity for K30. Since antibody ME20.4 inhibits NGF binding but antibody NGFR5 does not, these antibodies bind to distinct epitopes. However, these epitopes apparently are closely spaced since these antibodies compete with each other for binding to biotinylated RED. NGF, but not the control protein cytochrome c, protects RED from papain digestion. Therefore, the P32 C terminus is important for the expression of the NGF binding site and the antibody-defined epitopes, even though the NGF binding site and antibody-defined epitopes probably are not encoded by the P32 C terminus. These data suggest that complex interactions occur between different regions of the RED, and that optimum NGF binding requires the integrity of multiple RED domains, including a short sequence to the C terminus of residue 170.
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PMID:Structural domains of the extracellular domain of human nerve growth factor receptor detected by partial proteolysis. 137 92

Characteristic properties of the antigens recognized by sperm-immobilizing monoclonal antibodies (SI-mAbs) from different sources were compared by ELISA competitive inhibition assay, Western blot analysis, chromatographic analysis, and enzymatic digestion studies. Among 9 SI-mAbs, human mAb H6-3C4 and three mouse mAbs--2C6, 2B6, and 2E5--also possessed strong sperm-agglutinating activity. Binding of human mAb H6-3C4 to sperm was strongly inhibited by the three mouse mAbs (2C6, 2B6, and 2E5), but not by the rat or the other four mouse mAbs. SDS-PAGE revealed that mAb H6-3C4 and three mouse mAbs recognized the same antigen molecules of 15-25 kDa present in both sperm extracts and seminal plasma. Chemical treatments with trifluoromethanesulfonic acid and sodium metaperiodate destroyed the antigen determinants recognized by the above four mAbs, as detected by both ELISA and antibody absorption tests. Western blot analysis revealed that the antigens were susceptible to treatments with papain, proteinase K, and N-glycanase, but resistant to trypsin, V8 protease, and thermolysin. These results indicate that one of the major antigens recognized by mAbs with sperm-immobilizing action may be a sperm membrane-associated glycoprotein of 15-25 kDa and the epitope may involve N-linked oligosaccharides.
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PMID:Comparative studies of the antigens recognized by sperm-immobilizing monoclonal antibodies. 161 9

Results are presented on the observation of sequence-specific fragmentation of proteins in the 13- to 29-kDa mass range (ribonuclease A, papain, and proteinase K) by 252Cf-plasma desorption mass spectrometry. For these proteins, extensive N-terminal an, cn + 2, and dn fragment ions are observed with mass accuracies approaching 200 ppm for the most prominent fragment ions. The fragmentation pattern of these proteins shows the same fundamental behavior (arginine-directed, charge-remote fragmentation) that is observed in the fragmentation of small peptides, indicating that similar processes are occurring when large proteins and small peptides fragment in plasma desorption mass spectrometry.
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PMID:Fragmentation of proteins in the 13- to 29-kDa mass range observed by 252Cf-plasma desorption mass spectrometry. 163 Nov 12

The sequence- and stereospecificity of the S1- and S' i-subsites (i = 1-3) of bovine alpha-chymotrypsin and trypsin, proteinase K and penicillin amidase from E. coli and A. viscosus has been determined by hydrolysis and kinetically controlled peptide synthesis using different substrates. The data are compared with results for other serine proteases and the thiol protease papain. The stereospecificities differ by orders of magnitude, decreased when the enzyme was immobilized and were influenced when organic solvent molecules were bound to the enzyme.
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PMID:Stereo- and sequence specificity of serine proteases in peptide synthesis. 182 58

The arrangement of the large (70,000-Mr) and small (30,000-Mr) subunits of succinate dehydrogenase in the mitochondrial inner membrane was investigated by immunoblot analysis of bovine heart mitochondria (right-side-out, outer membrane disrupted) or submitochondrial particles (inside-out) that had been subjected to surface-specific proteolysis. Both subunits were resistant to proteinase treatment provided that the integrity of the inner membrane was preserved, suggesting that neither subunit is exposed at the cytoplasmic surface of the membrane. The bulk of the small subunit appears to protrude into the matrix compartment, since the 30,000-Mr polypeptide is degraded extensively during limited proteolysis of submitochondrial particles without the appearance of an immunologically reactive membrane-associated fragment: moreover, a soluble 27,000-Mr peptide derived from this subunit is observed transiently on incubation with trypsin. Similar data obtained from the large subunit suggest that this polypeptide interacts with the matrix side of the inner membrane via two distinct domains; these are detected as stable membrane-associated fragments of 32,000 Mr and 27,000 Mr after treatment of submitochondrial particles with papain or proteinase K, although the 27,000-Mr fragment can be degraded further to low-Mr peptides with trypsin or alpha-chymotrypsin. A stable 32,000-34,000-Mr fragment is generated by a variety of specific and non-specific proteinases, indicating that it may be embedded largely within the lipid bilayer, or is inaccessible to proteolytic attack owing to its proximity to the surface of the intact membrane, possibly interacting with the hydrophobic membrane anchoring polypeptides of the succinate: ubiquinone reductase complex.
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PMID:Topography of succinate dehydrogenase in the mitochondrial inner membrane. A study using limited proteolysis and immunoblotting. 199 68

The mitochondrial energy-linked nicotinamide nucleotide transhydrogenase is a homodimer of monomer Mr = 109,228. Hydropathy analysis of its cDNA-deduced amino acid sequence (1043 residues) has indicated that the molecule is composed of 3 domains: a 430-residue-long hydrophilic N-terminal domain which binds NAD(H), a 200-residue-long hydrophilic C-terminal domain which binds NADP(H), and a 400-residue-long hydrophobic central domain which appears to be made up mainly of about 14 hydrophobic clusters of approximately 20 residues each. In this study, antibodies were raised to the hydrophilic N- and C-terminal domains cleaved from the isolated transhydrogenase by proteolytic digestion, and to a synthetic, hydrophilic pentadecapeptide, which corresponded to position 540-554 within the central hydrophobic domain. Immunochemical experiments with mitoplasts (mitochondria denuded of outer membrane) and submitochondrial particles (inside-out inner membrane vesicles) as sources of antigens showed that essentially the entire N- and C-terminal hydrophilic domains of the transhydrogenase, as well as epitopes from the central pentadecapeptide, protrude from the inner membrane into the mitochondrial matrix, where the N- and C-terminal domains would be expected to come together to form the enzyme's catalytic site. Treatment of mitoplasts with several proteolytic enzymes indicated that large protease-sensitive masses of the transhydrogenase are not exposed on the cytosolic side of the inner membrane, which agreed with the exception that the central highly hydrophobic domain of the molecule should be largely membrane-intercalated. Trypsin, alpha-chymotrypsin, and papain had little or no effect on the mitoplast-embedded transhydrogenase. Proteinase K, subtilisin (Nagarse), thermolysin, and pronase E each split the mitoplast-embedded enzyme into two fragments only, a fragment of approximately 70 kDa containing the N-terminal hydrophilic domain, and one of approximately 40 kDa bearing the C-terminal hydrophilic domain. The cleavage site of proteinase K was determined to be A690 -A691, which is located in a small hydrophilic segment within the central hydrophobic domain. This protease-sensitive loop appears to be exposed on the cytosolic side of the inner membrane. The proteinase K-nicked enzyme containing two peptides of 71 and 39 kDa was isolated from mitoplasts and shown to have high transhydrogenase activity.
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PMID:Mitochondrial energy-linked nicotinamide nucleotide transhydrogenase. Membrane topography of the bovine enzyme. 200 10


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