Characterization and partial purification of dl-glycerol-1-phosphatase from Dunaliella salina

A specific dl-glycerol-1-phosphatase (glycerol-1-phosphate phosphohydrolase, EC 3.1.3.21) has been identified in the halotolerant alga Duniella salina. The enzyme is highly specific for dl-glycerol 1-phosphate, requires magnesium for activity and has a neutral pH optimum. High sensitivity toward sulfhydryl reagents suggests the existence of a sulfhydryl group in close proximity to the active site. Due to instability the enzyme was only partially purified (40-fold). Activity measurements following polyacrylamide electrophoresis showed the enzyme to have a molecular weight around 86 kdaltons. It is suggested that the enzyme plays a major role in the mechanism of osmoregulation in Dunaliella.