One of three specific glucosyltransferases in pea (Pisum sativum) that successively add a β-D-glucosyl group first to O-3 of kaempferol, and then to O-2 of the previously added glucosyl group giving the 3-O-sophoroside and then the 3-O-sophorotrioside (see also EC 22.214.171.124, flavonol 3-O-glucosyltransferase and EC 126.96.36.199, flavonol-3-O-glycoside glucosyltransferase). TDP-glucose can replace UDP-glucose as the glucose donor but the reaction proceeds more slowly.
Jourdan, P.S. and Mansell, R.L. Isolation and partial characterization of three glucosyl transferases involved in the biosynthesis of flavonol triglucosides in Pisum sativum L. Arch. Biochem. Biophys.213 (1982) 434–443. [PMID: 6462109]