Stoichiometric studies of tannin-protein co-precipitation.
Co-precipitation of a series of galloylglucoses (hydrolysable tannins) with bovine serum albumin (BSA) was studied stoichiometrically by analysing both galloylglucoses and BSA in the precipitates using HPLC. BSA-precipitating ability increased mainly with an increase in the number of galloyl groups in a galloylglucose molecule but was also affected by the position of the galloyl group (penta- > tetra- > 2,3,6-tri- > 2,3,4-tri- >> di- >> monogalloylglucose). The precipitated BSA increased linearly with an increase in the number of galloyl groups bound to a BSA molecule. BSA-precipitating abilities of the galloylglucoses were closely related to their relative affinities for BSA. These results suggest a two-stage mechanism: initial complexation of galloylglucose with BSA and subsequent precipitation, as a mechanism of the co-precipitation.
Kawamoto
H
H
Faculty of Agriculture, Kyoto University, Japan.
Nakatsubo
F
F
Murakami
K
K
D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D005960:Glucosides / Q000737:chemistry* / Q000302:isolation & purification; D009844:Oligosaccharides; D012710:Serum Albumin, Bovine / Q000302:isolation & purification*; D013329:Structure-Activity Relationship; D013634:Tannins / Q000737:chemistry / Q000302:isolation & purification*
D005960:Glucosides; D009844:Oligosaccharides; D013634:Tannins; D012710:Serum Albumin, Bovine