[Characteristics of thiamine-binding protein from rat brain synaptosomes].
The thiamine-binding protein was obtained from rat brain synaptosomes by affinity chromatography and gel-filtration on Sephadex G-200. The protein is homogeneous by the data of SDS gel-electrophoresis, anode electrophoresis and isofocusing between pH 3.5-9.0. The isoelectric point of this protein is near pH 4.8-5.0. The binding nature of the protein with [14C] thiamine was studied. It is shown that metal ions, especially Na+ and Ca2+, increase the thiamine-binding activity. The binding process is of a saturation character at the thiamine concentrations of 10(-7)-10(-5) M. Thiamine possesses two binding sites with KD1 = 3.1 microM and KD2 = 30 microM. Out of the tested thiamine analogues and antagonists of vitamin B1 thiamine-monophosphate and pyrithiamine were the most competitive.
V A
VA
Postoenko
Iu M
IuM
Parkhomenko
G V
GV
Donchenko
D000818:Animals; D001923:Brain Chemistry; D002352:Carrier Proteins / Q000302:isolation & purification*; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D008297:Male; D051381:Rats; D013574:Synaptosomes / Q000032:analysis*
D002352:Carrier Proteins; C026989:thiamine-binding protein
Kharakteristika tiaminsviazyvaiushchego belka sinaptosom mozga krys.