Study of interactions of different forms of glyceraldehyde-3-phosphate dehydrogenase with the chaperonin Hsp 70

Interaction of different forms of glyceraldehyde-3-phosphate dehydrogenase (GAPD) with the chaperonin Hsp 70 was investigated using enzyme-linked immunosorbent assay (ELISA). The developed approach is convenient for investigation of the interaction between Hsp 70 and GAPD (and presumably with other target proteins) and the influence of different effectors on this interaction. The assay is automatic and does not require large amounts of the proteins and their ligands. Both methods did not detect any interactions between native GAPD and Hsp 70. The addition of the substrate or cofactor or acylation of the enzyme did not induce its binding to Hsp 70. Denatured forms of GAPD obtained by the dissociation of the enzyme into subunits in a water solution or by the sorption of the enzyme on an ELISA plate efficiently bound to the chaperonin Hsp 70. It was demonstrated that denatured GAPD immobilized on Sepharose also interacted with soluble Hsp 70. Thus, we showed that the chaperonin Hsp 70 binds denatured forms of GAPD, which must prevent its participation in decomposition of amyloid structures (for example, aggregates of the huntingtin protein).