Isolation of six low molecular weight heat shock proteins and partial characterization of heat shock protein 29 from mung bean hypocotyl

Abstract

Heat shock protein (HSP29) together with five other low- M r HSPs have been isolated from mung bean hypocotyls by preparative continuous elution SDS-PAGE. Autoradiography and immunochemical analysis of 2D electrophoretograms of the radiolabelled HSP29 revealed that it consits of seven isotypes, two of which are constitutive while the other five are heat-inducible. The pI values of the seven isotypes range from 4.6 to 6.6. A monoclonal antibody raised against the HSP29 isolate reacted with six of the seven isotypes. When HSP29 was subjected to partial proteolysis by V8 Staphylococcus aureus protease (EC 3.4.21.19), two fragments of 12 and 17 kDa were identified, neither of which was recognized by the antibody.