Binding of plant isoperoxidases to pectin in the presence of calcium

AbstractSome of the isoperoxidases present in an extract from zucchini hypocotyls - one anionic and two cationic - exhibited a Ca2+-dependent pelletability which resulted from an interaction with pectins. Endogenous pectins could be replaced by polygalacturonic acid or pectin extracted from citrus, but not by highly esterifled pectin. The interaction between the isoperoxidases and the polysaccharides has been studied by centrifugation, by gel filtration, and with pectins attached in wells of a microtitration plate. These various binding tests have shown that the isoperoxidases had an affinity for the pectins in their Ca2+-induced conformation

Comprendre les pollutions par les métaux

International audienceUnderstanding metals pollutions Either from natural or anthropic origin, be it normal or accidental (Tchernobyl), metallic elements are found everywhere in our environment. After a presentation of their repartition and mobility in water, sediments or soils, the mechanisms allowing their dispersion or their concentration are shown. Finally, transfers between environmental compartments are presented, before evoking the case of polluted sites: diagnostic, remediation and long-time management