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)

A kallikrein-like kininogenase was identified in the rat adrenal gland. Most of the enzyme was present in an inactive form, since pre-incubation with trypsin markedly increased kininogenase activity from 54.8 +/- 11.8 to 230 +/- 23.0 pg bradykinin/mg protein/min. Adrenal kininogenase was inhibited 90% by phenyl methyl sulfonyl fluoride, 92% by D-Phe-Phe-Arg-chloromethylketone, 91% by aprotinin, and only 15% by soybean trypsin inhibitor. Pre-incubation with antibodies against rat urinary kallikrein resulted in 85% inhibition. The apparent molecular weight of adrenal kininogenase on gel filtration chromatography was 33 Kd. The enzyme was strongly adsorbed to immobilized rat urinary kallikrein antibodies and required drastic conditions for elution. In canine adrenal glands, we found that there was no difference in the cortical and medullary distribution of active and inactive SBTI resistant kininogenase activity. We conclude that an enzyme which closely resembles glandular kallikrein is present in adrenal glands.
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PMID:Glandular kallikrein-like enzyme in adrenal glands. 261 63

We have developed a sensitive and specific radioimmunoassay which allows the detection of human glandular kallikrein in biologic fluids at a level of 40 pg/ml. The antisera did not recognize human plasma kallikrein and glandular kallikrein from other species including marmoset. Furthermore the antibody did not bind pro-kallikrein but was specific for the trypsin activated kallikrein. The antibody inhibited the kininogenase activity of standard kallikrein incubated with human kininogen. However active kallikrein inhibited by inhibitors bound at the active site is still detectable, indicating that the antibody is specific for the structure of the active form but not for the active site. In normotensive subjects, daily urinary kallikrein excretion increased with age until 30, then a decrease was observed. In renal transplanted recipients a progressive increase of the active form was found. A low concentration of immunoreactive active kallikrein was detected in lymphatic fluids of patients suffering from acute pancreatitis treated by lymphatic drainage; although this kallikrein is the active immunoreactive form, a very weak kininogenase activity was measured, suggesting a partial inhibition by anti-proteases. These data provide complementary evidence for the physiological and pathological role of glandular kallikrein.
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PMID:Direct radioimmunoassay of active and inactive human glandular kallikrein: some physiological and pathological variabilities. 266 24

Human glandular kallikrein was purified from urine and subjected to detailed structural characterization. The protein was carboxymethylated with iodoacetic acid and digested with TPCK-trypsin, Staphylococcal aureus V-8 protease and endo LysC peptidase. The resulting peptide fragments were separated by reverse-phase HPLC using C-4 columns and acetonitrile-trifluoroacetic acid gradient elution. The complete amino acid sequence of the carboxymethylated derivative was elucidated by sequence analysis and alignment of peptides derived from different proteolytic cleavages. A procedure using in situ CNBr cleavage of a large endo LysC peptidase-derived peptide followed by direct sequencing was carried out to provide overlap for two glycosylation sites at residues 78 and 84. Three Asn-linked glycosylation sites were confirmed by the direct sequence analysis of the isolated glycopeptides. However, the third glycosylation at Asn-144 occurs only in 60% of kallikrein molecules. Reverse-phase HPLC effectively separates two species of HUK which correspond to molecules glycosylated and non-glycosylated at Asn-144, respectively. The human urinary kallikrein contains 238 amino acid residues with Ile and Ser as N- and C-terminal amino acids, respectively. The primary structure is completely identical to that deduced from a human genomic DNA sequence (F.K. Lin et al., manuscript in preparation) and is different in one amino acid (Lys-162 vs. Glu-162) from that deduced from pancreatic or kidney cDNA sequence.
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PMID:Human urinary kallikrein. Complete amino acid sequence and sites of glycosylation. 266 27

Glandular kallikrein (a trypsin-like serine protease) is a major estrogen-induced and dopamine-repressed protein in the rat anterior pituitary which appears to be associated with lactotrophs. In the pituitary the enzyme predominantly exists as a latent zymogen (pro-glandular kallikrein) which can be activated by trypsin. This study reports experiments employing biochemical techniques to investigate the subcellular localization of glandular kallikrein. Anterior pituitaries from estrogen-treated rats were fractionated on a discontinuous sucrose density gradient and the distribution of various organelles in the gradient was determined by conventional enzyme or protein marker assays. Each of the 8 organelle markers exhibited a unique distribution profile within the gradient. The distribution of glandular kallikrein was closely correlated (r = 0.91) with that of nucleoside diphosphatase (a marker for trans cisterna of the Golgi apparatus). For both glandular kallikrein and nucleoside diphosphatase, 35-45% of the total activity was found in Golgi zones of the gradient, and 18-22% was in the secretory vesicle fraction. In all of the subcellular fractions, 91-97% of the glandular kallikrein existed in the zymogen form (pro-glandular kallikrein). In Golgi fractions, 38% of the glandular kallikrein remained membrane-bound following freeze-thawing and two washes in hypotonic media; 94% of the nucleoside disphosphatase remained membrane-bound following such treatment. The results indicate that glandular kallikrein is most highly concentrated in trans cisternae of the Golgi apparatus with substantial activity also present in secretory vesicles. This localization is consistent with a role for glandular kallikrein as a prohormone processing enzyme in lactotrophs.
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PMID:Biochemical investigation of the subcellular localization of the estrogen-induced pro-glandular kallikrein in the rat anterior pituitary. 272 45

A trypsin-like serine proteinase, antigen gamma, immunologically partially identical to glandular kallikrein when run against anti-rat glandular kallikrein antiserum in immunoelectrophoresis, was purified from the rat submandibular gland. The enzyme was purified by a two-step chromatography procedure, ionexchange chromatography followed by gel filtration. The criteria for purity were one band in SDS-polyacrylamide gel electrophoresis and in immunoelectrophoresis, respectively. Antigen gamma had a molecular mass of 25,000 Da and consisted of two polypeptide chains with molecular masses of 14,000 and 11,000 Da. The preparation contained several isoenzymes with pI ranging from 4.1 to 4.5. The enzyme showed high specific enzyme activity against the substrate D-valyl-L-leucyl-L-arginine-4-nitroanilide (S-2266), some trypsin-like and kininogenase activity, but no angiotensin converting enzyme, kininase, or tonin activity. Amidolytic activity was increased and stabilized by the presence of detergent in the assay buffer. The pH-optimum of antigen gamma amidolytic activity was about 10. Antigen gamma was inhibited by SBTI and PMSF, whereas aprotinin had to be added in a more than 100 times higher concentration than for glandular kallikrein. The binding pattern of antigen gamma to plasma proteins was different from that of tonin and glandular kallikrein. Antiserum against antigen gamma was raised in rabbits and characterized against rat submandibular gland homogenate. Immunohistochemistry showed antigen gamma in the secretory granules of the submandibular gland granular tubular cells but only adhering to the luminal cell wall in the striated and main excretory ducts. Antigen gamma was not detected in the sublingual or parotid gland or in the kidney. Antigen gamma was demonstrated by immunoelectrophoresis in rat submandibular gland saliva. The concentration was higher in sympathetically than in parasympathetically induced secretion.
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PMID:Isolation, characterization, and localization of antigen gamma, a serine proteinase of the "kallikrein-family" in the rat submandibular gland. 282 44

The relationship between chemical modifications of arginine derivatives and inhibitory activity to trypsin, plasmin and glandular kallikrein was investigated comparing with that of thrombin and concluded as follows: The hydrophobic binding pocket, which has been reported previously to be stereogeometrically very similar in trypsin and thrombin, corresponded to the length of ethylpiperidine. Concerning the site (termed the P site) next to the hydrophobic binding pocket, there were large differences in stereogeometry between trypsin and thrombin; the binding site of trypsin extended further to allow propyl and phenyl group attached to piperidine, while that of thrombin would be much narrower and unable to allow them. The P sites of plasmin and glandular kallikrein resembled that of trypsin in being able to allow phenyl group. To substantialize the hydrophobic binding pocket and the P site, a (2R, 4R)-MQPA-trypsin complex model was generated using the results of X-ray crystallography of (2R, 4R)-MQPA and BPTI-trypsin complex by calculation to minimize van der Waals contacts, and it was of great use for understanding the geometry of the active sites of trypsin, thrombin, plasmin and glandular kallikrein.
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PMID:Similarity and dissimilarity in the stereogeometry of the active sites of thrombin, trypsin, plasmin and glandular kallikrein. 295 62

Glandular kallikrein is a major estrogen-induced protein of the rat anterior pituitary. A second kallikrein-like protease in the rat anterior pituitary (kallikrein A) is not affected by estrogens, nor is a third pituitary protease which cleaves a trypsin substrate but not kallikrein substrates. This study examined whether any of the pituitary proteases are regulated by dopaminergic mechanisms. Ovariectomized female rats were treated for 5-10 days with reserpine (a catecholamine depleting agent), haloperidol (a dopamine receptor blocker) or bromocriptine (a dopamine receptor agonist); some rats also received 1 or 2 micrograms estradiol benzoate every 48 h. Following activation of latent proteases with trypsin, anterior pituitary extracts were assayed for kallikrein activity before and after fractionation on DEAE-Sephadex to separate the two kallikrein-like proteases. Reserpine or haloperidol doubled glandular kallikrein levels in anterior pituitaries from estrogen-treated rats. Reserpine or haloperidol had little or no effect in the absence of estrogen (estrogen produced a 5- to 7-fold increase in glandular kallikrein in the absence of drug treatment). Bromocriptine markedly attenuated the ability of estrogen to induce glandular kallikrein. Further, bromocriptine blocked the ability of reserpine to increase glandular kallikrein levels, and haloperidol attenuated the effect of bromocriptine. Other anterior pituitary proteases were unaffected by either estrogen, haloperidol, reserpine or bromocriptine. The results demonstrate that the estrogen induction of glandular kallikrein in the rat anterior pituitary is modulated by inhibitory dopaminergic mechanisms. Prolactin is the only pituitary hormone which exhibits a similar profile of hormonal and neuroendocrine regulation; this suggests a possible link between glandular kallikrein and prolactin.
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PMID:Dopaminergic regulation of the estrogen-induced glandular kallikrein in the rat anterior pituitary. 302 15

A plasminogen activator inhibitor was purified from human cornified cell extract by DEAE-Sepharose, Sephacryl S-200, and high-performance liquid chromatographies on hydroxyapatite HPHT and anion-exchanger Mono Q at pH 7.2 and 8.0. The purified inhibitor showed Mr 43,000 and pI 5.2 50% inhibition of fibrinolytic activity (1.5 IU) of urokinase and tissue-type plasminogen activator was attained by 0.60 ng and 11.0 ng purified inhibitor, respectively. Synthetic substrate assay demonstrated slow tight-binding inhibition to both urokinase and tissue-type plasminogen activator. The inhibitor did not inactivate plasmin, thrombin, glandular kallikrein or trypsin.
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PMID:Purification of epidermal plasminogen activator inhibitor. 309 78

We have isolated and analyzed the gene for batroxobin, a thrombin-like snake venom enzyme. Three overlapping DNA segments containing the entire batroxobin gene were identified. Sequence analysis revealed that the batroxobin gene spans 8 kilobase pairs and contains five exons. Mature batroxobin is encoded by four separate exons, 2 to 5. The catalytic residues of batroxobin, His-41, Asp-86, and Ser-178, are encoded by separate exons, exons 2, 3, and 5, respectively. The exon/intron organization of the batroxobin gene is different from that of the prothrombin gene but very similar to those of the trypsin and kallikrein genes. These results indicate that batroxobin is not a member of the prothrombin family but one of the trypsin/kallikrein family. The snake venom gland is assumed to originate from the submaxillary gland. Therefore, batroxobin is expected to be a member of the glandular kallikrein family.
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PMID:Organization of the gene for batroxobin, a thrombin-like snake venom enzyme. Homology with the trypsin/kallikrein gene family. 316 91

The measurement of glandular kallikrein in biological fluids most often utilizes a synthetic substrate, H-D-valylleucylarginine-p-nitroanilide (S-2266), which assesses amidase activity. Although this substrate has reasonable specificity for glandular kallikrein, other tryptic-like proteases found in mixed saliva may also cause hydrolysis. The primary purpose of this study was to assess the accuracy of the use of this substrate for the measurement of glandular kallikrein in human mixed saliva. An additional objective was to determine the presence of prekallikrein in mixed saliva. The addition of soybean trypsin inhibitor (SBTI), which inhibits other tryptic-like enzymes but not glandular kallikrein, resulted in an approx. 30 per cent decrease in the hydrolysis of S-2266 by centrifuged mixed human saliva. A correlation of 0.918 was obtained between the biological assays for kinin release and amidase activity in 19 subject samples. Amidase activity increased following treatment of saliva with trypsin, indicating the presence of prekallikrein in human mixed saliva. It is concluded that S-2266 is an accurate substrate for the assay of glandular kallikrein in human mixed saliva; that the inclusion of SBTI in the assay mixture is needed to inhibit non-kallikrein proteases that may also hydrolyse the synthetic substrate; and that prekallikrein is present in mixed saliva. Thus any future studies of changes in the level of kallikrein in saliva may wish to consider the presence of both active and total levels of glandular kallikrein.
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PMID:The assay of glandular kallikrein and prekallikrein in human mixed saliva. 324 88


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