Accumulation of 14C-nicotinate by membrane preparations
Totskiĭ, V.N.; Ol'shanetskaia, V.A.
Biokhimiia 43(3): 555-563
1978
ISSN/ISBN: 0320-9725 PMID: 656490 Document Number: 134795
The incorporation of nicotinic acid (NA) into cells and mitochondria depends on temperature and the presence of glucose, is coupled with the activity of Na, K-ATPase and is disturbed by the energy exchange inhibitors. The addition of a sucrose liver extract or protein-containing fractions of the extract stimulates the 14C-NA accumulation by liver mitochondria. The stimulating effect of the extract on 14C-NA incorporation into mitochondria is retained after dialysis, but is removed upon boiling of the extract. It is assumed that the 14C-NA transport is operated by proteins: NA is incorporated (at least, partially) into liver cells, where it exists both in a free and proteinbound states. It has been found that there exist at least two protein fractions which bind 14C-NA.