| Autor: |
Lambeau, Gérard, Ancian, Philippe, Nicolas, Jean-Paul, Beiboer, Sigrid H.W., Moinier, Danielle, Verheij, Hubertus, Lazdunski, Michel |
| Zdroj: |
Journal of Biological Chemistry; March 1995, Vol. 270 Issue: 10 p5534-5540, 7p |
| Abstrakt: |
Specific membrane receptors for secretory phospholipases A2(sPLA2s) have been initially identified with novel snake venom sPLA2s called OS1and OS2. One of these sPLA2receptors (muscle (M)-type, 180 kDa) has a very high affinity for OS1and OS2and a high affinity for pancreatic and inflammatory-type mammalian sPLA2s, which might be the natural endogenous ligands of PLA2receptors. Primary structures of OS1and OS2were determined and compared with sequences of other sPLA2s that bind less tightly or do not bind to the M-type receptor. In addition, the binding properties of pancreatic sPLA2mutants to the M-type receptor have been analyzed. Residues within or close to the Ca2+-binding loop of pancreatic sPLA2are crucially involved in the binding step, although the presence of Ca2+that is essential for the enzymatic activity is not required for binding to the receptor. These residues include Gly-30 and Asp-49, which are conserved in all sPLA2s. Leu-31 is also essential for binding of pancreatic sPLA2to its receptor. Many other mutations have been considered. Those occurring in the N-terminal α helices and the pancreatic loop do not change binding to the M-type receptor. Conversion of pancreatic prophospholipase to phospholipase is essential for the acquisition of binding properties to the M-type receptor. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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