Isoprenoid enzyme systems of silkworm. II. Formation of the juvenile hormone skeletons by farnesyl pyrophosphate synthetase II.
Comparative substrate specificities of farnesyl pyrophosphate synthetases I and II purified from larvae of silkworm, Bombyx mori, were studied by use of the possible biosynthetic intermediates of juvenile hormones in the insect. In the presence of Mn2+ ions farnesyl pyrophosphate synthetase II showed higher activity than synthetase I and the corresponding enzyme from pig liver with the following substrate homologues: (Z)-3-methyl-2-pentenyl-, 3-ethyl-3-butenyl-, (2E,6Z)-3,7-dimethyl-2,6-nonadienyl-, and (2E,6Z)-3-ethyl-7-methyl-2,6-nonadienyl pyrophosphate. When (Z)-3-methyl-2-pentenyl-, 3-ethyl-3-butenyl-, and isopentenyl pyrophosphate were mixed and incubated with farnesyl pyrophosphate synthetase II, (2E,6E,10Z)-3,11-dimethyl-7-ethyl-2,6,10-tridecatrienyl-, (2E,6E,10Z)-3,7,11-trimethyl-2,6,10-tridecatrienyl, and a trace amount of (2E,6E,10Z)-3,7-diethyl-11-methyl-2,6,10-tridecatrienyl pyrophosphate, whose carbon skeletons were the same as those of juvenile hormone I, II, and O, respectively, were formed. (Z)-3-Methyl-2-pentenyl pyrophosphate was produced from 3-ethyl-3-butenyl pyrophosphate as a single product by the action of silkworm isopentenyl pyrophosphate isomerase, though the enzyme activity was much lower with this substrate than with the usual substrate, isopentenyl pyrophosphate.
D000818:Animals; D012831:Bombyx / Q000201:enzymology*; D002712:Chlorides; D004122:Dimethylallyltranstransferase / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism*; D007605:Juvenile Hormones / Q000096:biosynthesis*; D007700:Kinetics; D008345:Manganese / Q000494:pharmacology; D017895:Manganese Compounds; D013058:Mass Spectrometry; D013379:Substrate Specificity; D014166:Transferases / Q000378:metabolism*
D002712:Chlorides; D007527:Isoenzymes; D007605:Juvenile Hormones; D017895:Manganese Compounds; D008345:Manganese; D014166:Transferases; D004122:Dimethylallyltranstransferase; C025340:manganese chloride