Murakami M T, Gabdoulkhakov A, Genov N, Cintra A C O, Betzel C, Arni R K
Department of Physics, IBILCE/UNESP, Cristovão Colombo 2265, São José do Rio Preto, SP 15054-000, Brazil.
Biochimie. 2006 May;88(5):543-9. doi: 10.1016/j.biochi.2005.10.014. Epub 2005 Dec 5.
The electrophile Ca(2+) is an essential multifunctional co-factor in the phospholipase A(2) mediated hydrolysis of phospholipids. Crystal structures of an acidic phospholipase A(2) from the venom of Bothrops jararacussu have been determined both in the Ca(2+) free and bound states at 0.97 and 1.60 A resolutions, respectively. In the Ca(2+) bound state, the Ca(2+) ion is penta-coordinated by a distorted pyramidal cage of oxygen and nitrogen atoms that is significantly different to that observed in structures of other Group I/II phospholipases A(2). In the absence of Ca(2+), a water molecule occupies the position of the Ca(2+) ion and the side chain of Asp49 and the calcium-binding loop adopts a different conformation.
