生化学と分析生化学

概要

Surface Plasmon Resonance Based Recent Advances in Understanding Plant Development and Related Processes

Prachi Jain, Dhara Arora and Satish C Bhatla

Since its introduction in the early 1990s, SPR has now become a powerful research tool for studying specificity, affinity and real time kinetics of a broad range of biomolecular interactions, including protein-DNA, protein-protein, protein-carbohydrate, protein-RNA and protein-lipid interactions. Surface plasmon resonance (SPR) has provided crucial information on the mechanisms of molecular interactions accompanying varied aspects of plant development. The structure-function relationship of various lectins depends on the quaternary arrangement of its monomers. Novel findings have been made in plant hormone research using SPR as a technique. Thus, new salicylic acid binding proteins (SABPs) have been identified in Arabidopsis. These include α-ketoglutarate dehydrogenase E2 subunit, glutathione S-transferases, the oligopeptidases TOP2 and TOP1, and members of GAPDH protein family. By immobilizing biotin-labelled DELLA peptides on the sensor chip and AtGID1a [Arabidopsis gibberellic acid (GA) receptor] as analyte, GA4 has been observed to maximally enhance binding between DELLA and GID1. Molecularly imprinted monolayer (MIM)-decorated SPR detection method precisely differentiates between similar plant hormones, such as, IAA, 1H-indole-3-butyric acid (IBA) and kinetin (KT), with detection limits around sub-picomolar range. Coronatine Insensitive-1 (COI1) has been shown to act as a jasmonic acid receptor using SPR. Ricin, a plant toxin, was detected at a concentration 2,500 times less than the minimum lethal dose (200 ng.ml-1) using a SPR biosensor. Real time binding kinetic studies of viral proteins (VirE1 and VirE2) and ssDNA using SPR have shown that their binding is strongly influenced by substrate and it occurs at poly T sequences and not at polyA and dsDNA. An interaction between the replicase protein (p93) of cucumber necrosis tombusvirus (CNV) with the host protein, Hsp 70 (molecular chaperone), has revealed the potential role of Hsp90 in the assembly of viral replicase. SPR analysis from a small library of phytochemicals has shown ellagitannin geraniin as one of the most potent inhibitor of Hsp90 (a stabilizer of many oncoproteins). Future applications of SPR technique are likely to provide tremendous inputs into the molecular understanding of plant development and related processes.