Heterologous expression of a multifunctional wheat protein

RAMIRO PARIS; RUBEN CONDE

Puerto Madryn

Congreso; XLVI Reunion Anual; 2010

Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular

On the last years, increasing and detailed information about proteinstructure and function give place to the concept ofmultifunctionality on proteins. Germins and Germin Like Proteins(GLPs) constitute a large and highly diverse family of ubiquitousplant proteins. A wide range of activities is found among Germinsand GLPs such as seed storage, sugar and hormone binding andstructural protein. A remarkable biochemical attribute of GLPs istheir resistance to desiccation, extreme pH, denaturalization andproteolysis. Previous studies at our lab showed an apoplastic GLPfrom wheat leaf, which has been characterized as SOD, AGPPase,and protease inhibitor (PI). The multifunctional protein was namedafter his later activity as GLPI and was also involved on plantpathogen defense mechanisms. Comparative genomic analysis ofthe GLPI sequence placed it on the subfamily 2 of GLPs, alongbarley GLPa2. Aiming to generate tools for the study of thestructure and biochemical activities of GLPI, we expressedrecombinant GLPI (rGLPI) fused to a N-terminal His tag. BacterialrGLPI was affinity purified and showed PI activity overcommercial trypsin on zymograms. These results indicated thatactive GLPI could be heterologously expressed and open thepossibility of using it as molecular tool for structural andbiochemical studies of protein multifunctionality.