ISSN:
1432-2048
Keywords:
Chloroplasts
;
Chromoplasts
;
Isopentenyl diphosphate
;
Narcissus
;
Polyprenoids
;
Spinacia
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Purified spinach chloroplast and daffodil chromoplast preparations do not use mevalonate, phosphomevalonate, and diphosphomevalonate for the synthesis of isopentenyl diphosphate. Isopentenyl diphosphate, on the other hand, is incorporated into plastidal polyprenoids in large amounts. In the presence of a cytoplasmic supernatant, however, mevalonate and the phosphomevalonates were incorporated into the plastidal polyprenoids in equally large amounts, which demonstrates that the enzymes mevalonate kinase (EC 2.7.1.36), phosphomevalonate kinase (EC 2.7.4.2), and diphosphomevalonate decarboxylase (EC 4.1.1.33) are soluble cytoplasmic enzymes and that they apparently do not occur as isoenzymes within the plastids. The concept is developed that isopentenyl diphosphate is a central intermediate in plant polyprenoid formation which is channeled into several compartment for different biosynthetic pathways.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00385544
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