A new approach for studying interaction of the polygalacturonase-inhibiting proteins with pectins

摘要: Abstract A method for determination of the interaction between pectins and proteins was developed using cross-linked polygalacturonic acid (CLPG) as pectic substrate polygalacturonase-inhibiting (PGIPs). Defined water-insoluble were prepared by chemical substitutions with acetyl or methoxyl groups on CLPG. In presence 0.1 M NaCl, PGIPs fully bound to CLPG but not alginic (CLAL), which had a similar p K CLPG, suggesting that inhibitor simply nonspecific electrostatic interaction. Optimum binding occurred at pH 2.4 4.7. The ability CLPGs degree methylation (DM) 66% acetylation (DAc) 133% significantly changed. contrast, DM 82% 95% decreased binding. These results indicated carboxylic galacturonic residues involved in recognition PGIPs.