Interaction of rat alpha-fetoprotein and albumin with polyunsaturated and other fatty acids: determination of apparent association constants.
The interaction of fatty acids with rat alpha-fetoprotein and albumin was measured using a partition equilibrium method. alpha-Fetoprotein (AFP) displays one high-affinity binding site for fatty acids and albumin near two binding sites. The AFP association constants for most fatty acids were similar to those of albumin (in the 10(7) M-1 range) whereas for docosahexaenoic acid it was 9.7 x 10(8) M-1, about 50-fold higher than that corresponding to albumin. This difference justifies docosahexaenoic acid in fetal or neonatal serum being mainly bound to AFP and can indicate a highly specific role of AFP in the transport of this fatty acid.
Anel
A
A
Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza, Spain.
Calvo
M
M
Naval
J
J
Iturralde
M
M
Alava
M A
MA
Piñeiro
A
A
D000818:Animals; D005230:Fatty Acids, Nonesterified / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D007700:Kinetics; D011485:Protein Binding; D051381:Rats; D012709:Serum Albumin / Q000378:metabolism*; D000509:alpha-Fetoproteins / Q000378:metabolism*
D005230:Fatty Acids, Nonesterified; D005231:Fatty Acids, Unsaturated; D012709:Serum Albumin; D000509:alpha-Fetoproteins