After the cells of spinach leaveswere broken, the chlorplasts, peroxisomes, microsomes, and the 100 000×g supernatant fraction were obtainedby differential centrifugation or gradient density centrifugation. The occurrence of betaine aldehyde dehydrogenase (BADH) in these fractions wastested using two methods: (1 ) assayingthe activity of BADH in each fractionby a spectrophotometric method, and(2 ) immunodetection of BADH ineach fraction with the antiserum against BADH from spinach leaves.BADH was not detected in chloroplastsby the spectrophotometric method(Table 1 ), but found by immunoassaymethods (Figs. 1 and 3). Besided thechloroplasts, BADH was also found inthe other organelles, including perokisomes and microsomes, and in the100 000×g supernatant by the abovetwo methods (Table 1, Figs. 2 and3). These results show that BADH is akind of cytoplasmic enzyme.
Betaine aldehyde dehydrogenase, localization, cell organelle, spinach