Catalysis of the reaction: -4-O-methyl-D-glucuronic acid + H2O = -OH + methyl-D-glucuronic acid. This reaction is the hydrolysis of the ester linkage between 4-O-methyl-D-glucuronic acid (MeGlcA) and an alcohol (-OH) group attached to a molecule, denoted here as .
glucuronoyl esterase activity