Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

In our previous research, we found that the level of the plasminogen activity in the plasma from Duchenne-type patients with progressive muscular dystrophy was higher than of the normal boys, though the level of the plasmin inhibitors was lower. Therefore, in the present study, we investigated the differences in the fractions of plasmin inhibitors. The subjects were nine patients (the average age being 17.1 years) who had been diagnosed, by clinical and biochemical tests, as having PMD; serving as controls were normal boys (the average age being 15 years), the patients' mothers, and the mothers of the normal boys. The plasmin inhibitors were separated from plasma using lysine-Sepharose columns according to the method of Urita et al. The determination was performed based on the method of Aoyagi et al. and an immunoreactive assay. The results were as follows: (1) No significant differences were seen between patients with PMD and control subjects with respect to either alpha 1-antichymotrypsin, antithrombin III, and alpha 1-antitrypsin or alpha 2-macroglobulin and inter-alpha-trypsin inhibitors. These results suggested that the low level of plasmin inhibitors in patients was due to the low activity of the C1 inactivator. (2) The patients with PMD showed lower values than the normal boys in the levels of C1 inactivator in plasma; similarly, the mothers of these patients showed lower values than the normal mothers.
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PMID:Plasma plasmin inhibitors in Duchenne-type progressive muscular dystrophy. 316 Mar 43

The capacity of purified tryptase from human lung mast cells to metabolize human fibrinogen, fibrin, and plasminogen was evaluated. Tryptase (5 micrograms/ml) inactivated the thrombin-induced clotting activity of fibrinogen (100 micrograms/ml) with essentially similar t 1/2 values of 4.6 min in the absence of heparin and 5.8 min in the presence of heparin (20 micrograms/ml) that were not appreciably different than with lysine-Sepharose-purified plasmin (5 micrograms/ml). Fibrinogen treated with tryptase together with heparin lost all detectable clotting activity by 4 hr at 37 degrees C, whereas fibrinogen treated with tryptase alone resulted in destruction of only 80% of fibrinogen clotting equivalents after 16 hr. Tryptase alone was observed to cleave only the alpha-chains of fibrinogen by electrophoresis of tryptase-treated, denatured, and reduced fibrinogen in polyacrylamide gradient gels. Tryptase together with heparin cleaved first the alpha-chain and then the beta-chain, the latter cleavage corresponding to complete loss of fibrinogen clotting activity by 4 hr. No fibrinogen fragments with anticoagulant activity were generated by tryptase. In contrast, plasmin left no residual clotting activity after 4 hr of incubation and generated fibrinogen fragments with anticoagulant activity. Plasmin sequentially cleaved the alpha, beta, and gamma subunits of fibrinogen. Tryptase alone (6 micrograms/ml) or together with heparin (20 micrograms/ml) failed to activate plasminogen (0.6 mg/ml) after a 60-min incubation at 37 degrees C. Addition of urokinase to tryptase-treated or untreated plasminogen resulted in essentially identical plasmin activities (0.32 and 0.34 U/ml, respectively), indicating that tryptase neither activates nor destroys plasminogen. Tryptase (700 ng) also failed to substantially solubilize cross-linked fibrin (2.6 micrograms) or the corresponding amount of fibrinogen bound to plastic microtiter plates with or without heparin. The failure to solubilize fibrinogen and, possibly, fibrin is consistent with the observation that the apparent m.w. by SDS polyacrylamide gel electrophoresis of unreduced fibrinogen is not appreciably altered by prior treatment with tryptase, even though cleavage of alpha-and beta-chains is revealed after reduction. Fibrinogenolysis by tryptase complements other mast cell mediators with anticoagulant properties such as heparin and suggests a significant prevention of coagulation by activated mast cells.
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PMID:The fibrinogenolytic activity of purified tryptase from human lung mast cells. 316 48

This study reports on the presence of latent plasminogen activator (PA) activity in human amniotic fluid (HAF). To measure PA, HAF was incubated with plasminogen, and the formation of plasmin was followed by its ability to cleave globin. The latent proenzyme in HAF was converted to active PA by treatment with sodium dodecyl sulphate (SDS) but not by tryptic digestion. The level of SDS-activatable PA activity in HAF increased with increasing gestational age. In an alternative, direct assay of PA based on its amidolytic activity upon L-pyroglutamyl-glycyl-L-arginine-p-nitroanilide (S-2444), HAF PA activity could be demonstrated even without prior exposure to SDS. Medium conditioned with either chorion or amnion produced PA activity suggesting that HAF PA is derived from the fetal membranes. Treatment of the conditioned medium with SDS or trypsin further increased the enzyme activity. The fetal membranes also produce inhibitory activities towards exogenous trypsin, plasmin, and urokinase. The inhibition of plasmin could be separated from the inhibitory activities towards trypsin and urokinase by DEAE-sephadex ion-exchange chromatography. The function of PA in the normal physiology and in pathological processes involving HAF and the fetal membranes remains to be elucidated.
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PMID:Plasminogen activator activity and urokinase inhibitor activity in human amniotic fluid and fetal membranes. 323 41

The fate of circulating inactive prorenin was examined in patients and volunteers. Prorenin was activated either by acid-dialysis with warming at pH 3.3 or with trypsin. The results were similar but omission of warming reduced the value by 13%. In 6 volunteers, 20 min forearm venous occlusion raised regional total (T) and inactive (I) plasma renin concentration (PRC) by 51% and 48% without change of active (A) renin. During intense forearm exercise the ratio APRC: IPRC did not change in muscle or skin venous blood. Body anaerobic exercise increased APRC 3.7-fold without change in IPRC. These procedures activate plasminogen but are without effect on prorenin. In 18 patient with stable angina, TPRC was lower in coronary sinus than arterial blood (p less than 0.001) but APRC was not affected. A-V differences were not detected across the leg. Prorenin is apparently stable in the circulation but extracted by the heart.
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PMID:Potential functions of plasma prorenin; regional activation and tissue extraction. 330 99

Recent evidence indicates that human alveolar macrophages can degrade purified elastin in vitro by a cell contact-dependent process involving acidic proteinases of the cysteine proteinase class. It is unclear to what extent these cells can degrade elastin within a natural extracellular matrix. To address this question, we cultured live human alveolar macrophages on elastin-rich, 3H-lysine-labeled, extracellular matrices deposited by rat smooth muscle cells in vitro. Under various culture conditions, we then measured release of total radioactivity from the matrices during co-culture with cells as well as net loss of desmosine/isodesmosine as a specific marker of elastin degradation. Live macrophages adhered to and progressively solubilized matrix protein at a slow rate (approximately 5 micrograms/10(6) cells/24 h) but the rate of solubilization increased more than 15-fold in the presence of plasminogen. The elastin component of the complicated matrix was not measurably degraded in the absence of plasminogen, but in medium containing plasminogen, 3.5 X 10(6) macrophages degraded 25 +/- 8 micrograms of elastin in 72 h. After pretreatment of matrices with trypsin to remove glycoprotein elements, live cells degraded 16 +/- 4 micrograms of elastin under plasminogen-free conditions. The addition of serum to the medium (1 to 5%) inhibited degradation of elastin within whole matrices (approximately 50% compared to serum-free medium containing plasminogen) but had no effect on degradation of elastin in trypsin-pretreated matrices. An active site inhibitor of cysteine proteinases, Z-phenylalanine-phenylalanine-diazomethylketone, blocked approximately 50% of the elastin degradation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Role of plasminogen activator in degradation of extracellular matrix protein by live human alveolar macrophages. 334 31

At least six allelic forms of apolipoprotein(a), differing in molecular mass, could be detected by immunoblot analysis. One of these phenotypes with a molecular mass of 570 kDa has been investigated. After reduction and carboxymethylation it was digested with trypsin and the resulting peptides were separated by gel filtration and reverse phase HPLC. The tryptic fragments sequenced comprised a total of 356 amino acids. The N-terminus of apo(a) was highly homologous to the start of the kringle 4 domain from human plasminogen and the majority of the tryptic peptides isolated was also homologous to sequences from this kringle. At least five homologous "kringle 4" domains are present in apolipoprotein(a) whereby one domain occurs more frequently than the others. A carbohydrate-rich peptide was also obtained in high yield. This glycopeptide connects two "kringle 4" domains and contains one N-glycoside within the kringle and six potential O-glycosides in the linking region. From the recovery it can be estimated that this peptide occurs several times within the whole apolipoprotein (a) sequence. The high carbohydrate content is in sharp contrast to that of human plasminogen. Other peptides sequenced indicate that apo (a) also contains domains homologous to the kringle 5 and protease regions of plasminogen. No unique peptides were found. These studies suggest that apolipoprotein (a) could have arisen through duplication of specific regions from the human plasminogen gene. The size heterogeneity of apo (a) might then be explained by differences in the numbers of gene duplications.
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PMID:Structural relationship of an apolipoprotein (a) phenotype (570 kDa) to plasminogen: homologous kringle domains are linked by carbohydrate-rich regions. 344 97

Apolipoprotein(a) [apo(a)] is a glycoprotein with Mr approximately equal to 280,000 that is disulfide linked to apolipoprotein B in lipoprotein(a) particles. Elevated plasma levels of lipoprotein(a) are correlated with atherosclerosis. Partial amino acid sequence of apo(a) shows that it has striking homology to plasminogen. Plasminogen is a plasma serine protease zymogen that consists of five homologous and tandemly repeated domains called kringles and a trypsin-like protease domain. The amino-terminal sequence obtained for apo(a) is homologous to the beginning of kringle 4 but not the amino terminus of plasminogen. Apo(a) was subjected to limited proteolysis by trypsin or V8 protease, and fragments generated were isolated and sequenced. Sequences obtained from several of these fragments are highly (77-100%) homologous to plasminogen residues 391-421, which reside within kringle 4. Analysis of these internal apo(a) sequences revealed that apo(a) may contain at least two kringle 4-like domains. A sequence obtained from another tryptic fragment also shows homology to the end of kringle 4 and the beginning of kringle 5. Sequence data obtained from two tryptic fragments show homology with the protease domain of plasminogen. One of these sequences is homologous to the sequences surrounding the activation site of plasminogen. Plasminogen is activated by the cleavage of a specific arginine residue by urokinase and tissue plasminogen activator; however, the corresponding site in apo(a) is a serine that would not be cleaved by tissue plasminogen activator or urokinase. Using a plasmin-specific assay, no proteolytic activity could be demonstrated for lipoprotein(a) particles. These results suggest that apo(a) contains kringle-like domains and an inactive protease domain.
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PMID:Partial amino acid sequence of apolipoprotein(a) shows that it is homologous to plasminogen. 347 6

Developing neurons and Schwann cells have been shown to secrete proteases. The influence of these proteases on neurite outgrowth by cultured sensory ganglia was examined by adding specific protease inhibitors. Neonatal mouse dorsal root ganglia were cultured directly on tissue-culture plastic dishes in serum-free N2 medium with different protease inhibitors. Soybean trypsin inhibitor was found to double the extent of neurite outgrowth by 4 days in vitro. Ovomucoid trypsin inhibitor and leupeptin also increased neurite outgrowth, while alpha 1-antitrypsin, antipain and phenylmethylsulfonyl fluoride elicited a smaller effect. Furthermore, added trypsin or thrombin inhibited neurite outgrowth and the inhibition could be reversed by soybean trypsin inhibitor, while exogenous plasminogen or urokinase were inhibitory only at high concentrations. Thus neurite outgrowth probably requires a closely regulated system of protease secretion and protease inhibitor production.
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PMID:Effect of proteases and their inhibitors on neurite outgrowth from neonatal mouse sensory ganglia in culture. 354 23

A plasminogen-binding site of human alpha 2-plasmin inhibitor was studied. The chromatogram of digest from the amidinated alpha 2-plasmin inhibitor (67K-daltons, plasminogen-binding form) with trypsin was almost identical with that obtained from the 65K-daltons derivative (non-plasminogen-binding form) treated with the same procedure, except for the three tryptic peptides. One of the three peptides, the deamidinated peptide T-11, was found to have a strong ability to inhibit the interaction of alpha 2-plasmin inhibitor with human plasmin. Moreover, the dissociation constant Kd for interaction between the peptide T-11 and plasmin was estimated to be 5.5 microM, indicating that Kd is about 10-fold lower than that of epsilon-aminocaproic acid. The sequence of the peptide T-11 was determined by the Edman method as follows: NH2-G-D-K-L-F-G-P-D-L-K-L-V-P-P-M-E-E-D-Y-P-Q-F-G-S-P-K-COOH. alpha 2-Plasmin inhibitor and its 65K-daltons derivative were found to have the same NH2-terminal sequence of Asn(Asp)-Gln-Glu-Gln-. These results indicated that the plasminogen-binding site(s) of alpha 2-plasmin inhibitor could be located in the COOH-terminal region of its molecule and that some of epsilon-NH2-groups in the deamidinated peptide T-11 may be involved in the lysine-binding site(s) of plasmin(ogen).
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PMID:Identification of the plasminogen-binding site of human alpha 2-plasmin inhibitor. 374 42

The amino acid sequence of the single polypeptide chain of bovine plasminogen (786 residues, Mr 88092) was determined. Cleavage with CNBr yielded 13 fragments of which six originated from cleavage sites different from human plasminogen. Digestion with elastase gave three major fragments: kringles (1 + 2 + 3) and kringle 4, both with intact lysine binding sites, and mini-plasminogen. Subfragmentation was achieved mainly with 2-(2-nitrophenylsulfenyl)-3-methyl-3'-bromoindolenine (BNPS-skatole), Staphylococcus aureus V8 protease and trypsin. The sequences of fragments which were determined by automated Edman degradation, were aligned with overlapping sequences, or, in a few instances, by homology with the known sequence of human plasminogen. Sequence comparison with the human protein showed varying degrees of homology in the different functional and structural domains. The overall identity (78%) is practically the same as that found in those regions corresponding to the heavy (79%) and the light chain (80%) of plasmin. The average degree of identity among the kringles is 83%. Outside the kringle structures the extent of identity decreases, to 65% in the N-terminal region and to about 50% in the connecting strands between the kringles except for the strand between kringles 2 and 3, where only one out of 12 residues is exchanged. The results reported show that bovine plasminogen apparently contains the same structural and functional domains as human plasminogen. Bovine plasminogen also contains two carbohydrate moieties. The only partially substituted N-glycosidic site, Asn289, corresponds to partially glycosylated Asn288 in human plasminogen, whereas the O-glycosidic site of the human sequence, Thr345, is shifted to Ser339 in bovine plasminogen.
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PMID:Complete amino acid sequence of bovine plasminogen. Comparison with human plasminogen. 384 32


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