Mario de Andrade: The Creative Works

Phytoalexins: Enzymology and Molecular Biology

“…The activity of this h a s e has been demonstrated in a number of plants (376)(377)(378)(379)(380)(381)(382)(383)(384)(385)(386)(387)(388)(389). Table VI shows some of the properties of the enzyme (378,389,390). A comparative study of the molecular weights of the enzyme from various plant and animal sources has been presented by Gray and Kekwick (390).…”

“…A partially purified preparation which could not be resolved into isoenzyme forms by gel-filtration displayed a pH optimum of 7.0 (Table VI). Mevalonate lunases from other plant sources show pH optima of 6.5 or above (378,384,386,387). The b a s e generally requires MnZ+ or Mg2+ for activity and is in some cases activated by thiol compounds (384,386) and inhibited by some of the products of the acetate-mevalonate pathway (Table VI).…”

“…A comparative study of the molecular weights of the enzyme from various plant and animal sources has been presented by Gray and Kekwick (390). The enzymes from Phaseolus vulgaris (384), Hevea brasiliensis latex (378), and Pinus pinasrer (391) have been partially purified. In earlier studies, two forms of the enzyme were demonstrated in P. vulgaris (381,382), one form with a pH optimum of 7.5 being located in the chloroplast, and the second, with an optimum of pH 5.5, being of extra-chloroplast origin (see also Ref.…”