Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine the cellular localization of glandular kallikrein in the human pancreas, immunohistochemical studies were performed with a monospecific antibody against the antigenically identical urinary kallikrein (urokallikrein). The localization of glandular pancreatic kallikrein to the beta cells of the islets was the same as that of insulin in normal human pancreas and in two islet-cell tumors. When beta cells were lacking in islet-cell tumors or in the pancreas of a patient with juvenile-onset diabetes, kallikrein antigen was not detectable. Anti-urokallikrein absorbed with purified urinary or pancreatic kallikrein no longer identified a pancreatic antigen, whereas absorption with insulin had no effect. The beta-cell localization of human pancreatic kallikrein, an endopeptidase that, in concert with carboxypeptidase B, converts bovine proinsulin to a polypeptide with the electrophoretic mobility of insulin, suggests that pancreatic kallikrein may be involved in the physiologic activation of proinsulin.
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PMID:Identification of human glandular kallikrein in the beta cell of the pancreas. 22 May 34

A pancreatic endopeptidase localized to the beta-cells of the pancreas by immunohistochemical techniques has been purified to homogeneity by following its functional and antigenic characteristics as a glandular kallikrein (EC 3.4.21.8). The enzyme gave a single stained band on alkaline disc gel electrophoresis which corresponded in location with the kinin-generating activity eluted from a replicate gel, was of 54,000 molecular weight by gel filtration, was devoid of caseinolytic activity, elicited a monospecific antiserum in a rabbit, and gave a line of complete identity with a single constituent in pancreatic extract, crude urine, and purified urokallikrein when analyzed with monospecific antibody to urokallikrein. The pancreatic glandular kallikrein generated three cleavage products of increasing anodal mobility from bovine and porcine proinsulin, and the presence of pancreatic kininase or bovine carboxypeptidase B increased the quantity of these products. Although the conversion products did not correspond to diarginyl- and monoarginylinsulin, the product of intermediate mobility was also obtained when proinsulin was treated with a low concentration of trypsin in the presence of kininase. The most rapidly migrating product did correspond to desalanylinsulin in the reference standard. Kininase alone had no action on proinsulin, and aprotinin prevented cleavage by kallikrein alone or in combination with kininase. Although the chemical structure of the proinsulin cleavage products has not been established, human pancreatic kallikrein is considered a putative activator of proinsulin because of its location in the beta-cell, its preferential action on proinsulin and kininogen as compared to azocasein, and its capacity to generate insulin intermediate products that are further modified by human pancreatic kininase or bovine carboxypeptidase B.
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PMID:Sequential cleavage of proinsulin by human pancreatic kallikrein and a human pancreatic kininase. 38 42

Mouse nerve growth factor (NGF) is cleaved at a histidine-methionine bond to release an NH2-terminal octapeptide (NGF1-8). The enzyme responsible, beta-NGF-endopeptidase, is structurally and functionally similar to gamma-NGF and epidermal growth factor-binding protein (EGF-BP) and cleaves mouse low molecular weight kininogen to produce bradykinin-like activity. These data have suggested that, like gamma-NGF and EGF-BP, beta-NGF-endopeptidase is a mouse glandular kallikrein. Evidence for a physiological role for NGF1-8 encouraged studies to further characterize the structure and function of this enzyme. Purified beta-NGF-endopeptidase migrated as a single band on isoelectric focusing and reducing SDS-polyacrylamide gels. As was expected, it removed NGF1-8 from NGF. Interestingly, enzymatic activity on an artificial substrate, and on NGF, was inhibited by NGF1-8 and by bradykinin. These studies further supported the view that beta-NGF-endopeptidase acts on both NGF and kininogen. The first 30 NH2-terminal amino acids of beta-NGF-endopeptidase were sequenced. This analysis demonstrated that the enzyme is encoded by the gene designated mGK-22 (Evans et al., 1987). The sequence of this gene corresponds to that of EGF-BP type A (Anundi et al., 1982; Drinkwater et al., 1987), and so studies were performed to determine whether or not beta-NGF-endopeptidase participates in EGF complex formation. Chromatographic and kinetic data gave no evidence that beta-NGF-endopeptidase is an EGF-binding protein. Our studies suggest that contamination of high molecular weight (HMW) EGF preparations with beta-NGF-endopeptidase erroneously led to earlier designation of the product of mGK-22 as an EGF-BP.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:beta-NGF-endopeptidase: structure and activity of a kallikrein encoded by the gene mGK-22. 201 5

The two major species of arginine endopeptidase present in the soluble fraction of human submaxillary gland are glandular kallikrein and another enzyme tentatively named nonkallikrein arginine endopeptidase. In this study, we purified the latter enzyme to homogeneity and examined its catalytic properties. The newly found enzyme was clearly distinguishable from human tissue kallikrein in its molecular nature, action toward various synthetic substrates, and kinin-generated activity. The specificity of the action of the enzyme was further investigated using various basic amino acid-containing peptides as model substrates. HPLC analysis of peptide fragments produced, followed by their amino acid analysis, revealed that the enzyme preferentially hydrolyzed the Arg-Arg or Arg-Lys bonds in dynorphins A 1-10, 1-9, and 1-8, beta-neoendorphin, adenorphin, and neurotensin.
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PMID:Nonkallikrein arginine endopeptidase in the human submaxillary gland: purification and characterization of the enzyme. 785 81