Functions as crystallin in the rabbit eye lens. Has high L-gulonate 3-dehydrogenase activity. It also exhibits low dehydrogenase activity toward L-3-hydroxybutyrate (HBA) and L-threonate. L-gulonate + NAD(+) = 3-dehydro-L-gulonate + H(+) + NADH Inhibited by malonate and by inorganic phosphate. Homodimer. Detected in eye lens, kidney, liver, heart, lung, brain and testis. Belongs to the 3-hydroxyacyl-CoA dehydrogenase family.