Possible function of two insect phospholipid-hydroperoxide glutathione peroxidases

We compared the functional properties of two insect members of the phospholipid hydroperoxide glutathione peroxidases (PHGPx) family, VLP1, a major component of virus-like particles from the hymenopteran endoparasitoid Venturia canescens and its closest Drosophila relative, one of the putative PHGPx-proteins predicted from the Berkeley Drosophila genome sequence project. Recombinant Drosophila PHGPx shows enzymatic activity towards a number of PHGPx substrates, while the recombinant PHGPx-like domain of VLP1 lacks a functionally relevant cysteine and enzyme activity. A possible function of a non-enzymatic extracellular PHGPx-like protein is discussed.