Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Psoriatic scale proteases were found to be extracted effectively in salt solution (1 mol/l) containing Triton X-100 (5 g/l). The extraction in dilute buffer or sucrose yielded low activities. The acid (0.25 N H2SO4) and KSCN (2 mol/l) solutions effectively extracted plasminogen activator. Fibrinolysin was most active in salt (1 mol/l KCl) and in KSCN (2 mol/l) extracts. Psoriatic scale proteases were fractionated by Sephadex G-100 gel filtration and further by DEAE cellulose chromatography. Five different enzyme preparations were obtained. The first preparation, resembling cathepsin D, effectively hydrolysed hemoglobin at pH 3.5 and casein at pH 5.8 and was insensitive to protease modifiers. The second preparation effectively hydrolysed trypsin substrates (AGLME, TAME, BAEE and BANA) and also histone and casein at pH 7.2 and was inhibited by protease inhibitors, TLCK and E-600. The third preparation hydrolysed histone and casein at pH 10.2 and was effectively inhibited by E-600 and partially by protease inhibitors and TPCK. The fourth preparation, resembling cathepsin B1, hydrolysed BANA and BAEE at pH 5.8 and was activated by SH-reagents and EDTA. The fifth enzyme preparation hydrolysed ATEE and was inhibited by E-600 and TPCK. Plasminogen activator was found mainly in the second enzyme preparation and fibrinolysin activity in the third and fifth enzyme preparations. The second, third and fifth enzyme preparations were different from the enzymes found in healthy human skin. The proteases of psoriatic scale resemble those of tissue and cell cultures undergoing rapid cell division. The possible role of proteases in the increased cell division in psoriasis plaque is discussed.
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PMID:Human skin proteases. Fractionation of psoriasis scale proteases and separation of a plasminogen activator and a histone hydrolysing protease. 0 31

In paramecia the membranes of alveoli and trichocysts are permanently connected to the cell membrane by membrane-junctions, which consist of membrane-intercalated particles in a regular geometrical arrangement. Trichocysts contain secretory material discharged by exocytosis. In unfixed or fixed cells these two compartments were impermeable to the following tracers: To "microperoxidases", i.e. a cytochrome c-derived heme-nonapeptide and a heme-undecapeptide (WM approximately 1650, 1900) applied in vivo, as well as to lanthanum and cytochrome c used during (La) or after (cytochrome c) fixation. The heme-nonapeptide was prepared by TPCK trypsin digestion of cytochrome c and subsequent purification by Sephadex gel chromatography--a simple and inexpensive new procedure resulting in preparations of high yield and purity. Tracers entered alveoli only when the plasmalemma and the alveolar membranes ruptured upon glutardialdehyde fixation. In no case were transmembraneous channels detectable in regions containing membrane-intercalated particles; this holds true for all tracers used and for freeze-fracture replicas obtained by tantalum-tungsten evaporation. With regard to attachment sites over trichocysts our results do not support the assumptions by others according to which exocytosis would be driven by an osmotic shift via transmembraneous channels (which would be analogous to inter-cellular coupling phenomena mediated by gap-junctions), unless such channels would be assumed to operate as carriers rather than via diffusion. Tracers did not penetrate trichocysts before exocytosis occurred. The functional role of membrane-intercalated particles on trichocyst attachments remains unclear. Despite some resemblance with gap-junctions all types of intra-cellular membrane-junctions investigated are functionally "tight" at the level of "resolution" obtained with tantalumtungsten-shadowing and with the tracers used.
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PMID:Tracer and freeze-etching analysis of intra-cellular membrane-junctions in Paramecium with a note on a new heme-nonapeptide tracer. 17 81

The effects of trypsin inhibitors and phospholipase inhibitors on the acrosome reaction of washed cauda epididymal sperm of golden hamsters were studied using two different incubation systems. One incubation system, a non-synchronous acrosome reaction inducing system, included the use of a highly purified BSA and a protein-free motility factor preparation from hamster adrenal gland. The other system was a relatively synchronous acrosome reaction-inducing-system utilizing the calcium ionophore A23187. Acrosome reactions were inhibited by three low molecular weight synthetic trypsin inhibitors, benzamidine, NPGB and TLCK, when they were added five minutes prior to the initial occurrence of acrosome reactions in the non-synchronous system or five minutes prior to induction of acrosome reactions by A23187 in the synchronous system. Two phospholipase A inhibitors, p-bromophenacyl bromide and mepacrine, were also effective in inhibiting hamster sperm acrosome reactions in both incubation systems. TPCK, an inhibitor of several non-trypsin-like proteases, indomethacin, a prostaglandin synthetase inhibitor, and soybean trypsin inhibitor, a large molecular weight polypeptide, did not inhibit acrosome reactions. The inhibition of those acrosome reactions induced by A23187 provides further indirect evidence that the effective inhibitors were functioning at a site within the sperm. The overall results provide: (1) further support for our earlier work suggesting the involvement of an internal trypsin-like enzyme (presumably acrosin) rather than an exogenous trypsin-like enzyme in the hamster sperm acrosome reaction and (2) the first evidence suggesting the possibility that a sperm phospholipase may also be involved in the mammalian acrosome reaction.
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PMID:Further evidence in support of a role for hamster sperm hydrolytic enzymes in the acrosome reaction. 57 94

beta1-Bungarotoxin modified with p-bromophenacyl bromide (BPB) was reduced and carboxymethylated, and the resulting two constituent RCM-polypeptide chains (the RCM-A and B chains) were separated. The RCM-A chain was found to be modified by BPB by measuring its UV absorption spectrum and was shown to have lost one histidine residue by analyzing its amino acid composition. To determine the location of the modified histidine residue in the A chain of the toxin, the RCM-A chain was digested with TPCK-trypsin, and the resulting peptides were fractionated by gel filtration followed by DEAE-cellulose chromatography. The modified residue was finally identified as histidine-48 in the A chain by Edman degradation and from the amino acid composition of the BPB-modified peptide. The amino acid sequence around the modified histidine residue in the A chain is highly homologous with those of porcine pancreas phospholipase A2 and presynaptic toxin, notexin. We conclude that histidine-48 in the A chain participates in the phospholipase A activity of beta1-bungarotoxin.
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PMID:Characterization of phospholipase A activity of beta1-bungarotoxin from Bungarus multicinctus venom. II. Identification of the histidine residue of beta1-bungarotoxin modified by p-bromophenacyl bromide. 73 Jul 54

Commercial nisin was fractionated using a Bio-Gel P-10 column and ion-exchange chromatography on CM-sephadex C-25. Pure nisin having a titre of 40 X 10(6) units per gram was obtained. In polyacrylamide-gel electrophoresis the pure nisin gave three bands. It is suggested that heterogeneity of nisin is due to the presence of several biological polypeptides. The pure nisin is digested by chymotrypsin but it is not affected by TPCK-trypsin and pepsin.
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PMID:The use of gel-filtration for the isolation of pure nisin from commercial products. 82 Jan 64

On sequencing a hemoglobin a peptic hexapeptide with the amino acid composition Asp2, Gly, Val, Lys2 was isolated. Cleavage of this peptide with Tos-Phe-CH2Cl-trypsin resulted in the fragments Asp-Lys, Gly-Asp, Val-Lys, Asp--Lys-Gly-Asp, Asp-Lys-Val-Lys and Val-Lys-Gly--Asp. From these data two possible but inconsistent sequences for the hexapeptide can be derived: Asp-Lys-Val-Lys-Gly-Asp and Val-Lys-Asp-Lys-Gly-Asp. Fragments obtained by other cleavage procedures, direct sequencing of the globin peptide-chain with a sequenator as well as X-ray data of this hemoglobin show, that only the sequence starting with Asp occurs in the intact protein. Therefore the peptide Asp-Lys-Gly-Asp must have been formed by transpeptidation during sequence work. In order to verify this, Asp-Lys-Val-Lys-Gly-Asp was synthesized by an unequivocal, conventional procedure. Tryptic digestion of this hexapeptide also resulted in ASP-Lys-Gly-Asp in addition to the expected fragments. Thus it has been shown for the first time, that sequencing conditions may alter the constitution of a peptide.
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PMID:Transpeptidation in sequence analysis. Investigations concerning a native and a synthetic hexapeptide. 118 Dec 81

Two alkaline proteases, one splitting preferentially the substrates of chymotrypsin (ATEE) and the other one those of trypsin (BAEE), were separated and partially purified by chromatographic means from human skin extract made in a buffer containing 1.07 mol/1 KC1. The proteins soluble in dilute buffer were removed by a prior extraction. The enzymes could be separated effectively only in the presence of KC1 at a high conc-ntration since large molecular size aggregates or polymers were formed in solutions of low ionic strength. In the presence of 2 mol/1 KC1 the molecular size of the BAEE-hydrolysing enzyme was 120000 and that of the ATEE-hydrolysing enzyme 30000. The ATEE-hydrolysing enzyme was purified by Sephadex G-100 gel filtration and DEAE-cellulose chromatography about 250 fold. It also hydrolysed esters of tryptophane and phenylalanine as well as casein with optimum pH 7.8--8.2. The enzyme was inhibited effectively by LBTI, SBTI and partially by trasylol, TPCK and TLCK, but not by E-600 and SH-modifers. The hydrolysis of ATEE was doubled in the presence of 1 mol/lKCl, NaCl, KBr or NaBr but that of casein was inhibited to some extent. Human serum and alpha-1-antitrypsin inhibited this enzyme but not C1-inactivator. alpha-2-Macroglobulin did not protect if from inhibition by SBTI. The BAEE-hydrolysing enzyme was purified by Sephadex G-100 gel filtration and hydroxylapatite chromatography about 30 fold. It also split other esters of substituted basic amino acids as well as BAPA and histone proteins with optimum pH 7.5--8.2. It was inhibited by Trasylol and TLCK, but not by LBTI, SBTI, OMTI, TPCK, E-600, SH-modifiers, human serum, C1-inactivator or alpha-1-antitrypsin. Neither of these enzymes is exactly similar to any one of the enzymes so far separated from human tissues or fluids.
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PMID:Human skin proteases: separation and characterization of two alkaline proteases, one splitting trypsin and the other chymotrypsin substrates. 120 Jul 4

Controlled proteolytic digestion by trypsin or bacterial proteases limited to the cytosolic side of the native microsomal membrane is not efficient to inhibit glucose-6-phosphate hydrolysis. Modification of the microsomes with deoxycholate prior to protease treatment is prerequisite to allow accessibility of the integral protein and inhibition of enzyme activity. Glucose-6-phosphatase of native microsomes, however, is rapidly inactivated by micromolar concentrations of TPCK as well as TLCK. In deoxycholate-modified microsomes both reagents do not affect glucose-6-phosphate hydrolysis. These results indicate that in the native, intact microsomal membrane glucose-6-phosphatase is not accessible to proteolytic attack from the cytoplasmic surface. The putative inhibitory effect of some trypsin or bacterial protease preparations on glucose-6-phosphatase of native microsomes observed most possibly is a result of contaminating agents as TPCK or TLCK.
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PMID:Protease inhibitors but not proteases inhibit the glucose-6-phosphatase of native rat liver microsomes. 131 35

Fibrinogen fraction I (340 kDa) and fraction II (305 kDa) were isolated by glycine precipitation. The subunit chains of the two fractions were separated, after reduction, by reverse-phase high performance liquid chromatography. The amino acid compositions of the B beta and tau chains of fibrinogen II were identical with those of fibrinogen I. In contrast, the A alpha chains of fibrinogen II were composed of two populations, one comprising homogeneous, intact A alpha chains and the other consisting of heterogeneous, deficient A alpha chains (A alpha' chains) of lengths varying according to the sizes of their COOH-terminal defects. The molar ratio of the A alpha to the A alpha' chains in fibrinogen II was 1.16:1. The amino acid composition and sequence analyses of the TPCK-trypsin peptides derived from the A alpha' chains revealed that the COOH-terminal residues of the A alpha' chains were mainly Asn-269, Gly-297 and Pro-309. These results indicate that the fibrinogen II molecule is asymmetrical and can be represented by the formula (A alpha) (A alpha')(B beta)2(tau)2 and that fibrinogen II cannot be a plasmin degradation product of fibrinogen I.
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PMID:Human fibrinogen heterogeneity: the COOH-terminal residues of defective A alpha chains of fibrinogen II. 142 Aug 13

A number of enzymatic properties of fish pylochymopsin and bull chymopsin have been studied. Hydrolysis of synthetic ethers of N-benzoyl-L-tyrosine and N-benzoyl-L-arginine by these chymopsins depending at the time and concentration of preparations has been studied. It was found that bull chymopsin is the most active one. It was shown that concentrations of 2 to 6 micrograms/ml of bull chymopsin and of 15 to 20 micrograms/ml of fish enzyme were optimal for synthetic substrate BTME hydrolysis. The significant trypsin activity was revealed in the both preparations on a number of synthetic amides. In contrast to the bull chymopsin the treatment of fish pylochymopsin by TPCK did not completely remove the chymotryptic activity of pylochymopsin. It was shown that tryptic activity in the both preparations was completely removed with TLCK. The time and concentration dependence of the autolysis in both chymopsins has been studied. It should be noted that this process is negligible for fish pylochymopsin in contrast to bull chymopsin. Stabilization of both proteases in aqueous solution at room temperature has been studied. Stabilization of the chymopsins in solution is achieved by the addition of various protein preparations including casein and serum albumin. The degree of stabilization by these proteins was achieved at 2% concentration.
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PMID:[Enzymatic activity of chymopsin of various origin]. 151 48


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