Catalysis of the reaction: H2O + protein alpha-D-glucosyl-1,2-beta-D-galactosyl-L-hydroxylysine = protein beta-D-galactosyl-L-hydroxylysine + beta-D-glucose. The enzyme specifically hydrolyzes glucose from alpha-D-glucosyl- (1->2)-beta-D-galactosyl disaccharide units that are linked to hydroxylysine residues of collagen and collagen-like proteins.
protein-alpha-D-glucosyl-1,2-beta-D-galactosyl-L-hydroxylysine glucohydrolase activity