Reaction catalyzed by protein-L-isoaspartate(D-aspartate) O-methyltransferase (2.1.1.77)

		+			=			+
	S-adenosyl-L-methionine	+		protein L-isoaspartate	=		S-adenosyl-L-homocysteine	+		protein L-isoaspartate alpha-methyl ester