Lactose Synthase

**Definition:** An enzyme complex that catalyzes the transfer of GALACTOSE from UDP GALACTOSE to GLUCOSE, forming LACTOSE. The enzyme complex is composed of a B subunit, ALPHA-LACTALBUMIN, which changes the substrate specificity of the A subunit, N-ACETYLLACTOSAMINE SYNTHASE, from N-ACETYLGLUCOSAMINE to glucose making lactose synthesis the preferred reaction.

**Tree numbers:** - D05.500.299 - D08.811.913.400.450.400.500

**Synonyms:** - Lactose Synthetase