부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jcs.2007.11.001 Byline: Alexandre Evrard, Virginie Lagarde, Philippe Joudrier, Marie-Francoise Gautier Abbreviations: PIN-a, puroindoline-a; PIN-b, puroindoline-b Abstract: Puroindolines are two small, basic cysteine-rich proteins isolated from Triticum aestivum seeds and characterized by a tryptophan-rich domain. They form the molecular basis of wheat grain hardness and display antimicrobial activity that may contribute to plant defence. Their antimicrobial activity is presumed to be due to their hydrophobic tryptophan-rich domain. However, little is known about their mode of action and there is no in vivo evidence that the binding of puroindolines to membranes is mediated by their tryptophan-rich domain. In this study, using a yeast complementation assay, we showed that puroindolines interact with the Saccharomyces cerevisiae plasma membrane. By site-directed mutagenesis of their tryptophan-rich domain, we determined that two tryptophan residues (W41 and W44) are mandatory for interaction of puroindoline-a with the yeast membrane whereas interaction of puroindoline-b depends on lysine residues. These results highlight that other residues than tryptophan play a critical role in the interaction of puroindolines with membranes, and probably their affinity for lipids and antimicrobial activities. Author Affiliation: INRA, UMR1098 Developpement et Amelioration des Plantes, 2 Place Pierre Viala, F-34060 Montpellier Cedex 01, France Article History: Received 30 August 2007; Revised 24 October 2007; Accepted 6 November 2007