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

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.
 ...
PMID:Three-dimensional structure of fungal proteinase K reveals similarity to bacterial subtilisin. 637 21

An attempt was undertaken to determine the chemical nature of the neuralizing and lens-inducing effect of the retina and brain extracts from 7-8 day old chick embryos. These extracts were treated with immobilized enzymes (RNAse, proteinase K) and the effect of treatment was then estimated in the organ cultures (reacting tissue - early gastrula ectoderm). The effect of the enzymes was studied in different experimental variants which allowed to exclude the effect of the own proteases and temperature on the inducing activity of the extracts under study. The neuralizing activity of the retinal extract was shown to preserve after its treatment with RNAse but to be almost fully lost (or decrease) after proteolytic hydrolysis. Proteinase suppressed as well completely the lens-inducing effect of the extract from the chick embryo brain. A conclusion is drawn that the inducing activity of the extracts under study is due to proteins, rather than to RNA.
 ...
PMID:[Effect of heterogeneous inducers on the ectoderm of the early gastrula in Rana temporaria in vitro. IV. The inductive effect of embryonic tissue extracts after ribonuclease and proteinase treatment]. 676 28

We describe a novel radioimmunoassay procedure for the direct estimation of aldosterone in unextracted plasma and serum samples, in which interfering binding proteins are digested by Proteinase K (Tritirachium alkaline proteinase, EC 3.4.21.14), a powerful proteolytic enzyme. Heating at 75 degrees C for 15 min inactivates the enzyme before radioimmunoassay. Alternatively, EDTA may be used to inactivate the enzyme. The antibody-bound fraction is then precipitated with polyethylene glycol and isolated by centrifugation. This easy method eliminates extraction and purification and gives accurate and reliable results. The total time required for 100 estimations, including counting time, is about 6 h.
 ...
PMID:A direct radioimmunoassay for aldosterone in unextracted serum and plasma. 679 90

We have examined the effects of seven proteases on human placental tissue factor in Triton X-100, focusing on extracellular and cytoplasmic domains recognized by monoclonal antibodies HTF1, C28 1.1, and C28 2.1. Plasmin produced peptides recognized on Western blots by C281.1 but not HTF1. None of the other proteases destroyed the extracellular epitope without also removing the cytoplasmic epitope, and both trypsin and chymotrypsin removed the cytoplasmic epitope with little effect on the extracellular domain. Proteinase K destroyed both epitopes, as did neutrophil elastase when used at a relatively high concentration. When digests were sampled over time and reconstituted with lipids for determination of tissue factor activity, only proteinase K consistently produced a loss in tissue factor activity at four hours. After 24 hr, other enzymes also decreased the recovered activity, with the order of effectiveness elastase > trypsin > chymotrypsin.
 ...
PMID:Human placental tissue factor: protease susceptibility of extracellular and cytoplasmic domains. 750 71

Proteinase K has been employed to proteolyze peptides before their mass spectrometric analysis. This combination of the two methods yields abundant sequence ions in the mass spectrum, thus leading to an easy prediction of the primary structure of the peptide. It was found that both the variety of available sequence ions and also their abundances are increased strongly after proteinase K digestion, when compared with the normal mass spectrum. The shortcoming of little fragmentation encountered using conventional mass spectrometric ionization methods can mostly be overcome. The H'n and Y"m ions produced from proteolysis provided a double check of the peptide sequence.
 ...
PMID:Sequence-ion enhancement of peptides digested with proteinase K. 800 79

When crude deoxyribonucleic acid (DNA) preparations by boiling were used for the polymerase chain reaction (PCR) from pathogenic and non-pathogenic Yersinia enterocolitica strains, the amplified products were degraded after their storage at 4 C. The degradation of products was prevented by the addition of ethylenediaminetetraacetate (EDTA) or treatment with proteinase K. These findings indicate that Y. enterocolitica produced heat-stable deoxyribonuclease (DNase). Proteinase K treatment would be recommended to prevent heat-stable DNase contamination in the DNA preparations for PCR from Y. enterocolitica strains.
 ...
PMID:Degradation of a polymerase chain reaction (PCR) product by heat-stable deoxyribonuclease (DNase) produced from Yersinia enterocolitica. 804 2

Proteinase K from the fungus Tritirachium album Limber binds two Ca2+ ions, one strongly (Ca 1) and the other weakly (Ca 2). Removal of these cations reduces the stability of proteinase K as shown by thermal denaturation, but the proteolytic activity is unchanged. The x-ray structures of native and Ca(2+)-free proteinase K at 1.5-A resolution show that there are no cuts in the polypeptide backbone (i.e. no autolysis), Ca 1 has been replaced by Na+, while Ca 2 has been substituted by a water associated with a larger but locally confined structural change at that site. A small but concerted geometrical shift is transmitted from the Ca 1 site via eight secondary structure elements to the substrate recognition site (Gly100-Tyr104, and Ser132-Gly136) but not to the catalytic triad (Asp39,His69,Ser224). This is accompanied by positional changes of localized waters.
 ...
PMID:Crystal structure of calcium-free proteinase K at 1.5-A resolution. 808 13

This study determined the presence of two hemolytic activities in the oral treponeme, Treponema denticola, strains ATCC 35404 (TD-4), ATCC 33520, GM-1, and MS25. These activities, referred to as hemolytic and hemoxidative (HeA, HeO, respectively), were found to be both secreted into the extracellular environment, and cell associated. The extracellular activity was associated with small molecules with relative molecular weights of < 1000 Da, and its activity was cysteine independent; the cell-associated HeA and HeO activities were associated with a molecular weight fraction > 10 kDa, and were cysteine dependent. The HeO activity of the fractionated material observed was due to the oxidation of hemoglobin to methemoglobin, and preceded the HeA lysis of the RBCs by approximately 2 h. Heating at 80 degrees C and treatment with proteinase K resulted in the complete destruction of these activities in the fraction > 10 kDa, while lipase at high concentration (800 micrograms/ml) reduced the HeA and HeO activities in the extracellular fraction by approximately 50%. Proteinase inhibitors had a variable effect on HeA and HeO activities in both extracellular and cell-associated fractions. Scanning and transmission electron microscopy revealed a progressive destruction of the RBC membrane, with membrane protrusions formed early in the interaction, which progressed to irregular holes in the membrane, and the complete loss of membrane integrity.
 ...
PMID:Characterization of hemolysis and hemoxidation activities by Treponema denticola. 809 77

Proteinase K forms a 1:1 stable complex with its naturally occurring protein inhibitor, PKI3. The crystal structure of this complex has been determined by a combination of molecular replacement and single isomorphous replacement methods. The model comprises all of the 459 residues: 279 for proteinase K and 180 for PKI3, and it was refined to an R-factor of 19.2% at a resolution of 2.5 A. Association of these two molecules in the complex indicates the binding of PKI3 in the substrate recognition site of the enzyme. The active serine residue of proteinase K in this complex possesses a somewhat different configuration to that found in its native structure and hence renders the enzyme inactive.
 ...
PMID:The three-dimensional structure of the complex of proteinase K with its naturally occurring protein inhibitor, PKI3. 813 34

A riboprobe (RNA probe), corresponding to the 5' end of the HM175 hepatitis A virus (HAV) genome, was synthetized in vitro and was digoxigenin-labeled. Then the riboprobe was used to detect the CF53 HAV strain. Conditions of virus denaturation (with or without SDS and proteinase K, timing of assay) to release viral RNA were tested by dot-blot hybridization on a ten fold dilution of HAV suspension. Densitometric measures of dot-blot spots allowed to appreciate optimization of the method. Sensitivity of hybridization was compared with sensitivity of radioimmunoassay (RIA) and cell culture methods. Hybridization signals and scale of HAV suspension were consistent when 0.05% SDS, 0.17 micrograms/ml Proteinase K, 37 degrees C, 30 mn or 3 hours are used. 8.10(2) TCID50 HAV was detected by hybridization with digoxigenin-labeled RNA probes. Detection threshold was the same as radioimmunoassay and lower comparatively to cell culture.
 ...
PMID:[Detection of hepatitis A virus by riboprobe labeled with digoxigenin: comparison of methods]. 825 17


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