Studies on the diurnal rhythm of mevalonate metabolism by sterol and nonsterol pathways and of mevalonate-activating enzymes
Gonzalez-Pacanowska, D.; Aguilera, J.A.; Arce, V.; Garcia-Martinez, J.; Linares, A.; Garcia-Peregrin, E.
International Journal of Biochemistry 17(2): 275-278
ISSN/ISBN: 0020-711X PMID: 2989020 DOI: 10.1016/0020-711x(85)90127-2
Both in vivo and in vitro incorporation of mevalonic acid into nonsaponifiable lipids by 17-day-old chick liver and kidney did not show diurnal rhythm. Using 14CO2 production from MVA as an index of the shunt pathway not leading to sterols, we have demonstrated for the first time that there is no diurnal rhythm in this pathway. No significant differences were found in the specific activities of mevalonate kinase, mevalonate-5-phosphate kinase and mevalonate-5-pyrophosphate decarboxylase from chick liver and kidney throughout a period of 24 hr, using [1-14C]mevalonate as substrate. The absence of diurnal rhythm in the decarboxylase activity was corroborated by further experiments carried out using [2-14C]mevalonate-5-pyrophosphate as specific substrate of this enzyme.