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)

A human pancreatic beta cell tumor was maintained in monolayer cell culture for 80 days. The culture was terminated because of bacterial infection. Probably because extensive trypsin-collagenase dissociation was unnecessary, the dissociated cells attached much more quickly to the surface of the culture flask than do rat pancreatic cells obtained by enzymatic dissociation. Insulin release not only oscillated widely during the first 40 days of culture but also showed a decline from 380 mU the first week to about 50 mU/week the seventh week. For some unknown reason fibroblast overgrowth was not a major problem. Reduction of the medium glucose concentration from 16.5 mM to 5.5 mM did not alter insulin release rate. At glucose concentration of 16.5 mM, somatostatin 1.0 mug/ml reduced insulin release by 40%. From our previously reported studies on the effect of somatostatin on insulin release by monolayer cell cultures of rat endocrine pancreas, we conclude that the constant release of insulin by the tumor cells is relatively nonstimulated. We have confirmed that monolayer cultures of human pancreatic beta cell tumor do not represent a good model for normal human beta cell function because of the major shortcoming of an apparent inability to recognize glucose as a secretogogue.
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PMID:Monolayer cell culture of human pancreatic beta cell tumor: effect of glucose and somatostatin on insulin release. 17 3

Activation of human plasma prekallikrein by a bacterial metalloendopeptidase, Pseudomonas aeruginosa elastase, was reported (Shibuya et al. (1991) Biochim. Biophys. Acta 1097, 23-27). Details of the activation process were presently studied. The activation accompanied limited proteolysis of a peptide bond inside of a disulfide bridge of prekallikrein molecule. Amino acid sequencing analysis of the newly generated amino-terminal revealed that the cleavage site was Arg371-Ile372 bond which is the scissile bond in the activation of prekallikrein with trypsin-type proteinases. A pentapeptide substrate, 2-aminobenzoyl-Ser-Thr-Arg-Ile-Val-4- nitrobenzylamide, which contained the amino acid sequence identical to that around the scissile bond of prekallikrein was synthesized. Pseudomonal elastase, indeed, hydrolyzed the substrate at Arg-Ile bond with the kinetic parameters of Km = 118 microM, kcat = 1.56/s and kcat/Km = 1.33.10(4)/s M. These results indicated that the Arg371-Ile372 bond was sensitive not only to trypsin-type serine proteinases, but also a bacterial metalloproteinase. Kinetic analysis of the prekallikrein activation by pseudomonal elastase, however, revealed that the activation rate was slow, though the Km values was good enough to expect an occurrence of this activation in vivo (Km = 248 nM, kcat = 6.8.10(-4)/s, and kcat/Km = 2.7.10(3)/s M). The activation rate of prekallikrein by pseudomonal elastase in Hageman factor deficient plasma was remarkably improved when the plasma was reconstituted with purified Hageman factor molecule. From the results, a biological significance of the proteinase cascade in the plasma kinin generation was also indicated. The present in vitro study might support the hypothesis that the Hageman factor/kallikrein-kinin system plays an important role in bacterial infection including the pseudomonal one.
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PMID:Activation of human plasma prekallikrein by Pseudomonas aeruginosa elastase. II. Kinetic analysis and identification of scissile bond of prekallikrein in the activation. 154 86

Urinary trypsin inhibitory capacity is mainly due to the excretion of a glycoprotein which is immunologically related to the inter alpha-trypsin inhibitor and may be a proteolytic degradation product of that substance. It was tested in 133 subjects divided into 7 groups: 24 healthy controls (group A), 21 patients with bacterial infection (group B), 37 with bacterial infection under antibiotic therapy (group C), 25 with connective tissue disease (group D), 8 with infected connective tissue disease (group E), 14 with cancer (group F) and 4 with infected cancer (group G). Urinary trypsin inhibitory capacity level was very low in controls (3.32 +/- 0.8 U/g urinary creatinine), but it was dramatically increased when infection was present (149.67 +/- 23.6 U/g urinary creatinine). This test appeared to be more effective than serum C-protein measurement simultaneous carried out in the same patients. Urinary trypsin inhibitory capacity is not related to the degree of proteinuria in the urine sample, but it is increased in patients with chronic renal failure excluded from this study. Thus, its measurement is a sensitive, easy and useful test for detecting and monitoring infections. The return to its physiological value is a very good argument in favour of therapeutic effectiveness.
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PMID:[Clinical value of the determination of urinary antitrypsin activity]. 296 52

Necrosectomy with postoperative continuous local lavage was performed in a prospective study involving 95 patients with necrotizing pancreatitis. In the same period 567 patients with oedematous-interstitial pancreatitis were treated non-operatively with a hospital mortality rate of 0.7 per cent. In patients with necrotizing pancreatitis the median Ranson criteria score was 4.5 points; operation was required at a median of 7 days after the onset of symptoms because of non-response to conservative treatment. In all, 59 per cent of the patients (56 out of 95) developed extended intrapancreatic parenchymal necrosis, 70 per cent had ascites, and 66 per cent had intra- and extrapancreatic necrosis; 42 per cent of the patients had bacterial infection of the necrotic tissue. For lavage a median of 8 l/24 h of fluid were instilled postoperatively for 25 days (median). The lavage fluid showed high levels of immunoreactive trypsin, phospholipase A2, and endotoxin in the early postoperative period. Hospital mortality rate was 8.4 per cent. Necrosectomy and continuous postoperative lavage can achieve high survival rates in patients with necrotizing pancreatitis. Postoperative local lavage allows the continuous non-operative evacuation of biologically active compounds and devitalized tissue, and avoids damage to remaining vital exocrine and endocrine pancreatic tissue.
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PMID:Necrosectomy and postoperative local lavage in necrotizing pancreatitis. 334 26

Effects of human urinary trypsin inhibitor (MTI) against operative stress were investigated. Laparotomy in a mouse caused suppression of immunological functions such as phagocytic activity and antibody formation, followed by loss of resistivity to bacterial infection and acceleration of growth of concealed tumor. The operation also caused damages to the body such as enhancement of protein catabolism and suppression of renal function, followed by increase of blood urea nitrogen, increase of protease activity in skeletal muscle and suppression of PSP clearance. Since MTI wholly ameliorated these undesirable conditions of the body caused by operative stress, it was suggested that MTI has an effect on maintaining the homeostasis of the living body as well as the ability to inhibit trypsin.
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PMID:[Effects of human urinary trypsin inhibitor against operative stress]. 398 64

Previous work has shown that the Pseudomonas-derived protease, pseudomonas elastase (PAE), can modify transferrin to form iron complexes capable of catalyzing the formation of hydroxyl radical (.OH) from neutrophil (PMN)-derived superoxide (.O2-) and hydrogen peroxide (H2O2). As the lung is a major site of Pseudomonas infection, the ability of these iron chelates to augment oxidant-mediated pulmonary artery endothelial cell injury via release of 51Cr from prelabeled cells was examined. Diferrictransferrin previously cleaved with PAE significantly enhanced porcine pulmonary artery endothelial cell monolayer injury from 2.3-6.3 to 15.8-17.0% of maximum, resulting from exposure to H2O2, products of the xanthine/xanthine oxidase reaction, or PMA-stimulated PMNs. Iron associated with transferrin appeared to be responsible for cell injury. Spin trapping and the formation of thiobarbituric acid-reactive 2-deoxyribose oxidation products demonstrated the production of .OH in this system. The addition of catalase, dimethyl thiourea, and the hydrophobic spin trap, alpha-phenyl-n-terbutyl-nitrone, offered significant protection from injury (27.8-58.2%). Since sites of Pseudomonas infection contain other proteases, the ability of porcine pancreatic elastase and trypsin to substitute for PAE was examined. Results were similar to those observed with PAE. We conclude .OH formation resulting from protease alteration of transferrin may serve as a mechanism of tissue injury at sites of bacterial infection and other processes characterized by increased proteolytic activity.
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PMID:Protease-cleaved iron-transferrin augments oxidant-mediated endothelial cell injury via hydroxyl radical formation. 776 95

The equine alpha-1 proteinase inhibitor (alpha 1PI) system differs from that of man in that the equine system consists of four closely-linked genes (Spi1-Spi4) whereas in man, a single gene encodes for alpha 1PI. We have previously found differences in the proportion of the Spi proteins in equine serum and bronchoalveolar lavage fluid (BALF). We therefore wished to determine whether, as reported in man, there was any molecular weight difference between the Spi proteins in serum and BALF. alpha 1PI and albumin from equine BALF migrated further towards the anode compared with serum alpha 1PI on native polyacrylamide gel electrophoresis (PAGE) although the difference was only significant for alpha 1PI. Sodium dodecyl sulphate-PAGE (SDS-PAGE) showed that a mean decrease in molecular weight of 1.5 kDa for alpha 1PI and 1.3 kDa for albumin had occurred in BALF. These findings were observed in control animals and in those with symptomatic or asymptomatic chronic obstructive pulmonary disease. The mechanism of this decrease in molecular weight of alpha 1PI is likely to differ from reports of alpha 1PI cleavage by bacterial proteinases in man since the molecular weight change was relatively small and loss of trypsin inhibitory activity did not occur. Nor, in our system, was there evidence of bacterial infection. Damage by endogenous proteinases or glycosidases at a site other than the reactive site may be involved but the resultant effect on the efficiency of the antiproteinase screen of the lower respiratory tract is uncertain.
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PMID:Molecular weight alterations of alpha-1 proteinase inhibitor in equine bronchoalveolar lavage fluid. 785 28

We show that Escherichia coli produce a factor that inhibits the activity of tyrosine and serine/threonine protein kinases. The factor is a protein found in the periplasmic compartment and is also secreted into the culture medium. Using a particle concentration fluorescence immunoassay specific for tyrosine kinase activity and inhibition of the tyrosine kinase p56(lck), we purified this factor to apparent homogeneity. Analysis of trypsin-digested fragments by mass spectrometry identified the inhibitor as the bacterial periplasmic protein UDP-sugar hydrolase, an enzyme with potent and nonspecific 5'-nucleotidase activity. Overexpression of the enzyme in bacteria leads to coordinate increases in both 5'-nucleotidase and p56(lck) inhibitory activity, confirming the identity of the inhibitor. The kinase inhibitory activity appears to be due to the formation of adenosine, which we show is inhibitory for p56(lck), cAMP-dependent protein kinase, and casein kinase. Overexpression of UDP-sugar hydrolase leads to an increase in the recovery of enteropathogenic E. coli following infection of HeLa cell monolayers and corresponding alterations in tyrosine-phosphorylated host proteins. These results suggest that UDP-sugar hydrolase may be an important factor affecting host cell function following intracellular bacterial infection.
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PMID:Identification of a bacterial inhibitor of protein kinases. Mechanism and role in host cell invasion. 879 49

Two-hundred Wistar rats were allocated to 4 groups. The groups, 3 representing our acute pancreatitis model induced by intrabiliary injection of a trypsin/enterokinase mixture, were studied as follows: (A) no treatment; (B) given a daily 30-ml enema with 20 mg/kg rifaximin; (C) given a daily 30-ml enema with 20 mg/kg rifaximin plus lactitol 0.5 g/kg, and (D) given a daily 30-ml enema with warm saline. A further group of healthy rats was given an intrabiliary injection of 0.15 ml saline. Sacrifices were made after 6, 12, 24, 48 and 72 h of observation. Serial blood samples were drawn to measure pancreatic enzymes and endotoxin. At sacrifice, ascites, lymph nodes, pancreas, spleen, portal vein blood, arterial blood and bile were obtained for bacteriological culture. Both enema treatments brought about a significant improvement in survival. Enema treatments did not affect the serum level of pancreatic enzymes. A time-course increase in endotoxin level was observed in untreated rats. However, significantly decreased levels were observed after both enema treatments. Overall, ascites was the sample most frequently infected. Lymph nodes contiguous to the gut were found to be infected more frequently than those close to major vessels. The histological pancreatic damage was of a significantly lesser degree in both enema treatment groups. Virtually all severe necrotico-hemorrhagic pancreatic lesions were associated with bacterial infection. These data suggest that bacterial translocation plays a relevant role in the outcome of experimental necrotizing pancreatitis. Intra-abdominal spread and lymphatics seem to be the pathways most likely involved in such processes. Colonic cleansing by non-absorbable antibiotics and lactitol seems to exert a beneficial effect on the supervening infection of experimental necrotizing pancreatitis.
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PMID:Bacterial translocation in the course of acute pancreatitis: beneficial role of nonabsorbable antibiotics and lactitol enemas. 891 7

Infection by group B streptococci (GBS) is an important cause of bacterial disease in neonates, pregnant women, and nonpregnant adults. Historically, serotypes Ia, Ib, II, and III have been most prevalent among disease cases; recently, type V strains have emerged as important strains in the United States and elsewhere. In addition to type-specific capsular polysaccharides, many GBS strains possess surface proteins which demonstrate a laddering pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and resistance to trypsin digestion. These include the alpha C protein, the R proteins, and protein Rib. Some of these proteins elicit protective antibodies in animals. We demonstrate a trypsin-resistant laddering protein purified from a type V GBS strain by mutanolysin extraction and column chromatography. This protein contains a major 90-kDa band and a series of smaller bands spaced approximately 10 kDa apart on SDS-PAGE. Cross-reactivity of the type V protein with the alpha C protein and with R1 was demonstrated on Western blot (immunoblot). N-terminal sequence analysis of the protein revealed residue identity with 17 of 18 residues at corresponding positions on the alpha protein. Western blot of SDS extracts of 41 clinical type V isolates with rabbit antiserum to the protein demonstrated a homologous protein in 25 isolates (61%); two additional strains exhibited a heterologous pattern which was also demonstrated with 4G8, a monoclonal antibody directed to the alpha C protein repeat region. Rabbit antiserum raised to the type V protein conferred protection in neonatal mice against a type V strain bearing a homologous protein. These data support the hypothesis that there exists a family of trypsin-resistant, laddering GBS surface proteins which may play a role in immunity to GBS infection.
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PMID:A protective surface protein from type V group B streptococci shares N-terminal sequence homology with the alpha C protein. 892 97


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