Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1 Using fura-2 fluorometry of [Ca(2+)](i) in response to thrombin, trypsin and protease-activated receptor activating peptides (PAR-APs), we determined whether trypsin cleaves protease-activated receptor 1 (PAR1) and activates it in the endothelial cells of the porcine aortic valves and human umbilical vein. 2 Once stimulated with thrombin, the subsequent application of trypsin induced a [Ca(2+)](i) elevation similar to that obtained without the preceding stimulation with thrombin in the valvular endothelial cells. However, the preceding stimulation with trypsin abolished the subsequent response to thrombin, but not to bradykinin or substance P. 3 The response to PAR1-AP (SFLLRNP) was significantly (P<0.05) reduced by the preceding stimulation with thrombin and PAR1-AP in the valvular endothelial cells, while, importantly, it remained unaffected by the preceding stimulation with either trypsin or PAR2-AP (SLIGRL). The response to PAR2-AP was reduced by the preceding stimulation with trypsin and PAP2-AP. PAR1-AP attenuated the subsequent responses not only to thrombin and PAR1-AP but also to trypsin and PAR2-AP, while PAR2-AP specifically attenuated the subsequent responses to trypsin and PAR2-AP. 4 In human umbilical vein endothelial cells, a higher affinity PAR1-AP (haPAR1-AP) (Ala-pF-Arg-Cha-HArg-Tyr-NH(2)) specifically attenuated the responses to thrombin but not trypsin. On the other hand, the response to haPAR1-AP was significantly (P<0.05) attenuated by the preceding stimulation with thrombin but not trypsin. 5 In conclusion, trypsin cleaved PAR1 but did not activate it in the endothelial cells. Moreover, the trypsin-cleaved PAR1 was no longer responsive to thrombin.
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PMID:Unproductive cleavage and the inactivation of protease-activated receptor-1 by trypsin in vascular endothelial cells. 1252 81

We previously reported that gill group IB secretory phospholipase A(2) (sPLA(2)) exists as an inactive pro-sPLA(2) with the dipeptide Ala-Arg, at the N-terminus of mature sPLA(2) in mucous cells. Pro-sPLA(2) should be activated after being secreted to the surface of gill epithelia by trypsin-like protease. To clarify the above hypothesis, we investigated the existence of pro-sPLA(2) activating protease (PAP) in the gills of the red sea bream, using gill pro-sPLA(2) as a substrate. PAP was solubilized from the membrane fraction of the gills with 2% sodium cholate and partially purified by benzamidine-Sepharose chromatography and reversed-phase HPLC. Partially purified proteases, PAP1 and PAP2 showed a high molecular mass of about 200 kDa by gelatin zymography. PAP1 and PAP2 had optimal pH from 7 to 9 and were inhibited by trypsin inhibitors. These properties of PAP1 and PAP2 suggest that both enzymes belong to the membrane-associated trypsin-like serine protease family, such as enteropeptidase and corin. This is the first report verifying the existence of the activating protease of group IB pro-sPLA(2) isoforms in a non-digestive tissue.
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PMID:Partial purification and characterization of pro-phospholipase A2 activating proteases from gill membranes of the red sea bream, Chrysophrys major. 1582 Jan 42