Ornithine decarboxylase activity associated with a particulate fraction of brain |
| |
Authors: | S. C. Bondy |
| |
Affiliation: | (1) Department of Community and Environmental Medicine, University of California, 92715 Irvine, California;(2) Southern Occupational Health Center, 19722 MacArthur Boulevard, 92715 Irvine, California |
| |
Abstract: | The enzymic decarboxylation of ornithine by adult rat brain largely occurs in the particulate fraction. The activity is primarily due to ornithine decarboxylase (ODC) as evidenced by several criteria: i) the concurrent production of equimolar amounts of CO2 and putrescine, ii) the sensitivity of the reaction to difluoromethylornithine (DFMO), a specific inhibitor of ODC, iii) the lack of major effect of two inhibitors of ornithine-2-oxo-acid transaminase, upon the DFMO-sensitive component of decarboxylation, iv) the failure to profoundly reduce decarboxylation activity in the presence of a large excess of many aminoacids which could compete for non-specific decarboxylases. The insoluble ODC activity appears largely within synaptosomal and mitochondrial-enriched morphological fractions, yet cannot be attributed to trapped soluble ODC. Particulate ODC has a pH optimum and kinetic parameters that differ from those of soluble cerebral ODC. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|