Interactions of tea tannins and condensed tannins with proteins.
Binding parameters for the interactions of four types of tannins: tea catechins, grape seed proanthocyanidins, mimosa 5-deoxy proanthocyanidins, and sorghum procyanidins (mDP=17), with gelatin and bovine serum albumin (BSA) have been determined from isothermal titration calorimetry data. Equilibrium binding constants determined for the interaction with gelatin were in the range 10(4) to 10(6) M(-1) and in the order: sorghum procyanidins > grape seed proanthocyanidins > mimosa 5-deoxy proanthocyanidins > tea catechins. Interaction with BSA was generally weaker, with equilibrium binding constants of < or =10(3)M(-1) for grape seed proanthocyanidins, mimosa 5-deoxy proanthocyanidins and tea catechins, and 10(4)M(-1) for the sorghum procyanidins. In all cases the interactions with proteins were exothermic and involved multiple binding sites on the protein. The data are discussed in relation to the structures and the known nutritional effects of the condensed tannins.
Frazier
Richard A
RA
Department of Food Biosciences, University of Reading, PO Box 226, Whiteknights, Reading RG6 6AP, UK. r.a.frazier@reading.ac.uk
Deaville
Eddie R
ER
Green
Rebecca J
RJ
Stringano
Elisabetta
E
Willoughby
Ian
I
Plant
John
J
Mueller-Harvey
Irene
I
D000818:Animals; D002151:Calorimetry; D002417:Cattle; D005780:Gelatin / Q000737:chemistry / Q000378:metabolism*; D006860:Hydrogen Bonding; D015394:Molecular Structure; D008970:Molecular Weight; D044945:Proanthocyanidins / Q000737:chemistry / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D012867:Skin / Q000737:chemistry; D013634:Tannins / Q000737:chemistry / Q000378:metabolism*; D013662:Tea
D044945:Proanthocyanidins; D013634:Tannins; D013662:Tea; D012710:Serum Albumin, Bovine; D005780:Gelatin