Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

3[H]-Leucine incorporation into (pro)insulin and insulin secretion was investigated using islets prepared by collagenase digestion from pancreata of rats pretreated with the cholimimetic agent pilocarpine or with saline (controls). Under the influence of pilocarpine pretreatment the [3H]-leucine incorporation into islet proteins with insulin immunoreactivity is enhanced at 6 mM glucose in the incubation medium of the islets but the incorporated radioactivity at 18 mM glucose is independent of the pretreatment of the animals. Only small or no changes were found regarding insulin secretion. It is concluded that an influence of pilocarpine pretreatment should be taken into consideration using such islets for studies on the regulation of (pro)insulin biosynthesis.
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PMID:Influence of pilocarpine pretreatment on (pro)insulin biosynthesis of isolated islets of rats. 35 84

Leucine-binding protein described in an earlier paper was examined to characterize the dynamic properties of the system. Leucine-binding protein assembles into a large protein polymer or complex (greater than 302,000 daltons). Colchicine reduces and Mg2+ increases the amount of polymer formed. Trypsin destroys the isolated polymer but RNAase and collagenase do not. Mg2+-ATPase activity is present in the polymer fraction. The formation of the large complex suggests a quickly adaptable structure capable of responding to ionic and environmental conditions.
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PMID:Aggregation of binding protein from rat nerve. 72 98

Monolayer cultures of rabbit synovial fibroblasts stimulated with phorbol myristate acetate to produce large amounts of collagenase (EC 3.4.24.7) were used to study the biosynthesis and secretion of this enzyme. [3H]Leucine was added to cell cultures for pulse-chase and continuous-labelling experiments. The labelled procollagenase synthesized was identified by immunoprecipitation followed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and fluorography. The amounts of intracellular and extracellular proenzyme were quantified by measuring radioactivity incorporated into the proteins. procollagenase was synthesized as doublet proteins of Mr 57 000 and Mr 61 000. Immunoprecipitable proenzyme proteins were first detected in culture medium 35 min after [3H]leucine was added to the cells. Monensin treatment of the cells inhibited procollagenase secretion and led to intracellular accumulation of the proenzyme. Cells treated with tunicamycin produced only the 57 000-Mr form, indicating that in rabbit synovial cells the 61 000-Mr form was post-translationally modified by addition of oligosaccharides to asparagine residues. The ratios of glycosylated to unglycosylated forms in cell lysates and in culture medium were 0.22:1 and 0.07:1 respectively.
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PMID:Biosynthesis and secretion of procollagenase by rabbit synovial fibroblasts. Inhibition of procollagenase secretion by monensin and evidence for glycosylation of procollagenase. 631 Nov 79

Insulin secretion was monitored in monkey islets isolated by collagenase digestion and exposed to leucine and arginine with and without glucose. Leucine by itself (10 to 40 mmol/l) elicited concentration-dependent insulin secretion. At 40 mmol/l, leucine was approximately 60% as effective as glucose (16.7 mmol/l). The response to leucine was increased at low glucose concentrations. In high concentrations (20 and 40 mmol/l), arginine by itself was a poor stimulant. The effect of arginine was enhanced at low glucose concentrations (2.8 to 5.6 mmol/l). At high glucose concentrations neither amino-acid produced any significant further increase in insulin release.
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PMID:Effect of amino-acids on secretion of insulin by isolated islets of the monkey. 681 83