The Chl b Biosynthetic Pathway: Intermediary Metabolism

Abstract

In discussing the Chl b biosynthetic pathway, use will be made of kinetic analysis of precursor-product relationships in vivo. In 1988, equations were derived to investigate possible precursor-product relationships in branched, and interconnected pathways (Rebeiz et al. 1988; Tripathy and Rebeiz 1988). It was shown that for any two compounds A and B, formed from a common precursor P such as ALA, and having a possible direct precursor-product relationship between them, for any number of time intervals t1 to t2, the following equation describes the relationship between the specific radioactivity of compound A, possible radiolabel incorporation from compound A into compound B, and the net synthesis of compound B from compound A (Rebeiz et al. 1988): $$ {\bf Q}{{{\bf B}}_2}={(^{*}}{{{\bf A}}_1}{+^{*}}{{{\bf A}}_2})/2)\cdot {(^{*}}{{{\bf B}}_2}) $$