In vitro and in silico analysis of plant origin proteinase inbhibitor genes

Abstract

Serine PIs have been reported from a variety of plant sources and are the most studied class of PIs. This class is also known as Serpin family (Mello et aI. , 2002; Gettins, 2002; Hag and Khan, 2003; Rawlings et aI. , 2004; Christeller and Liang, 2005; Law et aI., 2006). All serine PIs from plants are competitive inhibitors and all of them inhibit proteinases with a similar standard mechanism (Laskowski and Kato, 1980). Serine PIs are universal throughout the plant kingdom, with trypsin inhibitors being the most common type. Two families of serine PIs that are PI-I and PI-II occur in tomato and potato. PI-I with a single reactive site inhibit chymotrypsin while PI-II type inhibit chymotrypsin and trypsin having two reactive sites. PI-II originally characterized from potato tubers (Christeller and Liang, 2005). The serine PI of Arabidopsis has been shown to play an important role in the plant immune response (Vercammen et al. , 2006). The core mechanism for this plant immune response is the up-regulation of complex pathways of host immune system by serine PIs (Law et aI. , 2006).