Initiating Structural Studies Of Lys49-Pla2 Homologues Complexed With An Anionic Detergent, A Fatty Acid And A Natural Lipid
Authors: Watanabe L.; Fontes M.R.M.; Soares A.M.; Giglio J.R.; Arni R.K.
Source: Protein and Peptide Letters, Volume 10, Number 5, October 2003 , pp. 525-530(6)
Publisher: Bentham Science Publishers
Abstract:Lys49-Phospholipase A2 (Lys49-PLA2 - EC 188.8.131.52) homologues damage membranes by a Ca2+- independent mechanism which does not involve catalytic activity. Both MjTX-II from Bothrops moojeni and BthTX-I from Bothrops jararacussu are dimeric in solution and in the crystalline states, and a model for the Ca2+-independent membrane damaging mechanism has been suggested in which flexibility at the dimer interface region permits quaternary structural transitions between open and closed membrane bound dimer conformations which results in the perturbation of membrane phospholipids and disruption of the bilayer structure . With the aim of gaining insights into the structural determinants involved in protein / lipid association, we report here the crystallization and preliminary X-ray analysis of the (i) MjTXII / SDS complex at a resolution of 2.78Å, (ii ) MjTX-II / STE complex at a resolution of 1.8 Å and (iii) BthTXI / DMPC complex at 2.72Å. These complexes were crystallized by the hanging drop vapour-diffusion technique in (i) HEPES buffer (pH 7.5) 1.8M ammonium sulfate with 2% (w / v) polyethyleneglycol 400, in (ii ) 0.6-0.8 M sodium citrate as the precipitant (pH 6.0-6.5) and in (iii) sodium citrate buffer (pH 5.8) and PEG 4000 and 20% isopropanol, respectively. Single crystals of these complexes have been obtained and Xray diffraction data have been collected at room temperature using a R-AXIS IV imaging plate system and graphite monochromated Cu K X-ray radiation generated by a Rigaku RU300 rotating anode generator for (i) and (iii) and using using a Synchrotron Radiation Source (Laboratorio Nacional de Luz Sincrotron, LNLS, Campinas, Brazil) for (ii ).
Document Type: Review article
Publication date: 2003-10-01
- Protein & Peptide Letters publishes short papers in all important aspects of protein and peptide research, including structural studies, recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, drug design etc. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallisation, and preliminary structure determinations of biologically important proteins are acceptable. Purely theoretical papers are also acceptable provided they provide new insight into the principles of protein/peptide structure and function.