Biosynthetic labeling of hypusine in mammalian cells. Carbon-hydrogen bond fissions revealed by dual labeling
Using a dual-label technique in which /sup 3/H- and /sup 14/C-labeled forms of putrescine and of spermidine were employed as biosynthetic precursors of hypusine, two -C-H bond cleavages were detected during production of this unique amino acid in Chinese hamster ovary cells. One of these cleavages occurs at C-1 of the 4-aminobutyl group during its transfer from the secondary amine nitrogen of spermidine to the nitrogen at the epsilon-position of a specific lysine residue in the polypeptide precursor of eukaryotic initiation factor 4D. Breakage of the other -C-H bond takes place at C-2 in this aminobutyl segment after it has been coupled to lysine to form the intermediate deoxyhypusine residue. Hydroxylation at this carbon atom, which constitutes the last step in hypusine biosynthesis, is the cause of bond cleavage. The data obtained are consistent with a notion that no additional -C-H bond fissions occur during hypusine biosynthesis. Our findings permit suggestion of a mechanism for enzymic aminobutyl group transfer in which 4-aminobutyraldehyde produced by oxidative cleavage of spermidine is coupled with the epsilon-amino group of a specific lysine residue to form an enzyme-bound imine intermediate.
- Research Organization:
- National Institute of Dental Research, Bethesda, MD
- OSTI ID:
- 6917379
- Journal Information:
- J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 30; ISSN JBCHA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Characterization of hypusine-containing 21,000-dalton protein in Neurospora crassa
Structural Analysis and Optimization of Context-Independent Anti-Hypusine Antibodies
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
BIOSYNTHESIS
CARBON 14 COMPOUNDS
CARBOXYLIC ACIDS
CHO CELLS
DOUBLE LABELLING
HAMSTERS
LABELLED COMPOUNDS
LABELLING
LYSINE
MAMMALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
RODENTS
SYNTHESIS
TRITIUM COMPOUNDS
VERTEBRATES