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)

Proteinase K (EC 3.4.21.14) from the fungus Tritirachium album Limber is the most active known serine endopeptidase. The sequence of its 275-residue long polypeptide chain and its three-dimensional folding show a high degree of homology with the bacterial subtilisin proteases. Using difference Fourier methods, the binding mode of the synthetic carbobenzoxy-Ala-Ala-chloromethyl ketone inhibitor to the active site of proteinase K was determined. In several cycles of restrained least-squares, the enzyme-inhibitor complex was refined to a current R = 22% for 9400 X-ray diffraction data between 2.2 and 5.0 A resolution. The inhibitor is attached to proteinase K by two covalent bonds: one between the methylene carbon of the inhibitor and N epsilon 2 of the catalytic His 68, the other between the ketone carbon atom of the inhibitor and O gamma of the catalytic Ser 221. In addition, two hydrogen bonds donated by the peptide NH of Ser 221 and by the side chain NH2 of Asn 160 hold the hemiketal O- in the oxyanion hole. The peptide inhibitor is further hydrogen bonded to the proteinase polypeptide chain in a three-stranded antiparallel pleated sheet.
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PMID:Active-site geometry of proteinase K. Crystallographic study of its complex with a dipeptide chloromethyl ketone inhibitor. 351 98

Ejaculated porcine and human spermatozoa, hamster spermatozoa from the cauda epididymidis, isolated hamster sperm heads and hamster cytoplasmic droplets contained activity that hydrolyzed the metalloendoprotease substrate ABZ-Ala-Gly-Leu-Ala-NBA (AAGLAN). Hamster sperm heads were isolated by treating spermatozoa with proteinase K and removing sperm tails with Dowex-50W beads. Hamster sperm activity was characterized using spermatozoa from which cytoplasmic droplets were removed by sonication and centrifugation. Porcine sperm preparations were essentially free of cytoplasmic droplets, while human sperm preparations retained somewhat more droplet material. Activity from all of these sources was inhibited by the metalloendoprotease inhibitors phosphoramidon, 1,10-phenanthroline, CBZ-D-Phe and CBZ-L-Phe but was not competitively inhibited by the metalloendoprotease substrate CBZ-Ser-Leu-amide. The AAGLAN hydrolyzing activity found in intact spermatozoa of all three species had a pH optimum of 6.2, while the optimum of the hamster sperm cytoplasmic droplet activity was 7.0. In addition, hamster sperm preparations were inhibited by ZnCl2 and dithiothreitol, but were not affected by toluene, benzamidine or chymostatin. The AAGLAN hydrolyzing activity of hamster sperm preparations was reduced, but not eliminated, by dialysis. It is concluded that spermatozoa from all three species, hamster sperm heads and hamster cytoplasmic droplets contain metalloendoprotease activity. Furthermore, metalloendoprotease activity found in hamster cytoplasmic droplets is different from that found in spermatozoa.
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PMID:Biochemical studies of metalloendoprotease activity in the spermatozoa of three mammalian species. 354 55

Natural abundance carbon-13 nuclear magnetic resonance spectra (67.9 MHz) were obtained for native nucleosome cores: cores dissociated in 2 M NaCl and 2 M NaCl, 6 M urea; and cores degraded with DNase I plus proteinase K. Phosphorus-31 NMR spectra of native and dissociated cores and core length DNA were also obtained at 60.7 MHz. The 31P resonance and spin-lattice relaxation time (T1) of DNA were only slightly affected by packaging in nucleosome cores, in agreement with other reports, but 13C resonances of DNA were essentially unobservable. The loss of DNA spectral intensity suggests that rapid internal motions of DNA sugar carbons in protein-free DNA previously demonstrated by 13C NMR methods are partly restricted in nucleosomes. The 13C spectrum of native cores contains many narrow intense resonances assigned to lysine side chain and alpha-carbons, glycine alpha-carbons, alanine alpha- and beta- carbons, and arginine side chain carbons. Several weaker resonances were also assigned. The narrow line widths, short T1 values, and non-minimal nuclear Overhauser enhancements of these resonances, including alpha- and beta-carbons, show that some terminal chain segments of histones in nucleosomes are as mobile as small random coil polypeptides. The mobile segments include about 9% of all histone residues and 25% of all lysines, but only 10% of all arginines. The compositions of these segments indicate that mobile regions are located in amino- or carboxyl-terminal sequences of two or more histones. In addition, high mobility was observed for side chain carbons of 45-50% of all lysines (delta and epsilon carbons) and about 25% of all arginines (zeta carbon) in histones (including those in mobile segments), suggesting that basic residues in terminal histone sequences are not strongly involved in nucleosome structure and may instead help stabilize higher order chromatin structure.
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PMID:Natural abundance carbon-13 nuclear magnetic resonance studies of histone and DNA dynamics in nucleosome cores. 370 Mar 80

The molecular mass of proteinase K was determined by gel electrophoresis in the presence of sodium dodecyl sulfate and by active site labelling with diisopropyl fluorophosphate. Both methods indicate molecular masses in the range of 27 000-29 000 Da. These values differ significantly from that of 18 500 formerly determined by gel filtration (Ebeling et al. (1974) Eur. J. Biochem. 47, 91-97). Proteinase K was inactivated with [3H]diisopropyl fluorophosphate. Afterwards the labelled protein was reduced, S-carboxymethylated and digested with cyanogen bromide. The chain lengths of the isolated CNBr-fragments are indicative of a molecular mass of proteinase K of at least 28 000 Da. Two CNBr-fragments were sequenced. The radioactively labelled fragment contains 69 residues and the sequence around the labelled residues was found to be -Ile-Ser-Gly-Thr-SER-Met-Ala-Thr-Pro-. This sequence is typical for that around the active site residue of the subtilisins. From the determined sequences it is concluded that the fungal proteinase K is phylogenetically related to the bacterial subtilisins.
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PMID:Proteinase K from Tritirachium album limber. I. Molecular mass and sequence around the active site serine residue. 392 77

Succinylacetone (SA) (4,6-dioxoheptanoic acid) is an abnormal metabolite produced in patients with hereditary tyrosinemia as a consequence of an inherited deficiency of fumaryl acetoacetate hydrolase activity. Patients with this disease are associated with a number of abnormalities, including aminoaciduria, proteinuria, liver failure, commonly hepatoma, and decreased GSH concentration in the liver. In the course of our studies of tyrosinemia, we found that the urine of patients with this disorder contains material(s) that absorbs light at 315 nm. We investigated the nature of the 315 nm material in detail. SA was found to react with amino acids and protein nonenzymatically, to form stable adducts at physiological temperature and pH. All SA adducts with amino acids and/or proteins exhibited an absorption peak at 315 nm. Although all amino acids reacted with SA, the most reactive amino acid was lysine (Lys), followed, in order, by glycine, methionine, phenylalanine, serine, alanine, and glutamine. SA-adducts were unstable at pH below 6, while they were made considerably more stable after reduction with NaBH4, suggesting that SA forms an adduct via Schiff base formation. High-performance liquid chromatography (HPLC) analysis of urines from patients with tyrosinemia revealed the existence of SA-glycine, SA-methionine, SA-tyrosine, and SA-phenylalanine. After digestion of urines with proteinase K, three more HPLC peaks appeared, which all corresponded to SA-Lys adducts. TLC analysis of SA-Lys showed that SA-Lys could form as many as seven different adducts. No SA-adduct peaks were observed in HPLC in urines from normal subjects, patients with other forms of aminoaciduria, or patients with the nephrotic syndrome. In addition to amino acids and proteins, SA reacted with reduced glutathione (GSH) and formed a stable adduct. These findings suggest that SA adduct formation with amino acids, GSH, and proteins is a significant process occurring in tyrosinemia, and may account for certain of the pathologic findings in this hereditary disorder.
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PMID:Hereditary tyrosinemia. Formation of succinylacetone-amino acid adducts. 392 1

Glucose dehydrogenase from B. megaterium is subjected to proteolysis with proteinase K. Upon proteolysis the enzyme is inactivated and the polypeptide chain is cleaved into two distinct fragments. These components designated as K-protein and K-peptide have molecular masses of 26 000 and 3 000 Da, respectively. Under native conditions the K-protein and K-peptide remain associated and the tetrameric structure of the proteolytically modified enzyme is preserved. The K-protein and K-peptide were isolated and characterised. The cleavage occurs in the C-terminal region of the polypeptide chain. -Leu Ala decreases Ser-Ser-Glu is proposed as the cleavage site.
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PMID:Limited proteolysis of glucose dehydrogenase from Bacillus megaterium by proteinase K. 641 54

Proteolysis of glucose dehydrogenase from Bacillus megaterium with proteinase K apparently generated two fragments. The small fragment, designated as K-peptide, was sequenced and its covalent structure was determined as Ser-Ser-Glu-Ala-Ser-Tyr-Val-Thr-Gly-Ile-Thr-Leu-Phe-Ala-Asp-Gly-Gly-Met-Thr- Gln-Tyr-Pro-Ser-Phe-Glu-Ala-Gly-Arg-Gly. The sequence analysis showed that the K-peptide consists of two identical fragments, one of which is lacking one serine residue at the amino-terminus.
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PMID:Amino acid sequence of the K-peptide generated by limited proteolysis of glucose dehydrogenase from Bacillus megaterium by proteinase K1. 642 50

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

Subtilisins (subtilopeptidase A, nagarse) and proteinase K were able to catalyze the synthesis of taurine-containing peptides from various N-acylated amino acid or peptide esters and nonprotected taurine. The synthesis was optimized using a model reaction between Boc-Tyr-OMe and taurine. The best results were obtained under strongly alkaline conditions in acetonitrile with low water content as the reaction medium. The choice of the base added to the reaction medium had a substantial effect on the product yield. A preparative synthesis of Tyr-Tau and Ala-Phe-Tau is described.
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PMID:Enzymatic approach to the synthesis of taurine-containing peptides. 789 5

Proteins or peptides having an N-terminal-blocked amino acid were successively digested by pronase E, proteinase K, and carboxypeptidase Y. The N-blocked amino acids released from proteins or peptides were derivatized with 9-anthryldiazomethane (ADAM) to the corresponding esters followed by addition of formic acid to remove the remaining ADAM which interfered with further analysis. The anthryl esters were analyzed by high-performance liquid chromatography equipped with a fluorimetric detector. Twelve N-acetylamino acids (Asn, Gln, Ser, Thr, Gly, Ala, Tyr, Pro, Met, Val, Ile, and Leu), pyroglutamic acid, N-formylMet, and N-myristoylGly could be separated from each other and identified on the same chromatographic run. As examples of applied experiments to proteins and peptides, N-acetyl derivatives of Ser, Ala, Met, Gly, Tyr, and Pro as well as N-myristoylGly could be satisfactorily identified using 100 pmol each of seven proteins and peptides. The method reported here is an improved one that was reported in the previous paper based on the same principles.
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PMID:Microidentification of N-terminal-blocked amino acid residues of proteins and peptides. 797 59


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