Isolation of metabolically-active subcellular particles from etiolated cotton seedling hypocotyls using bovine serum albumin in preparative medium

Abstract

Sub-cellular particles from cotton (Gossypium hirsutum L. var, Acala 1517C) seedlings prepared in 0.4 [image] sucrose-0.1 [image] phosphate at pH 7.0 and isolated by differential centrifugation exhibited very low or no suc-cinoxidase activity. Aliquots of these preparations severely inhibited an active soybean succinoxidase system, indicating the presence of a toxic principle in the cotton seedlings. This principle apparently inactivates the cotton particles following cell rupture. Inclusion of 2% (wt.-vol.) bovine serum albumin (BSA) in the preparative medium enabled the isolation of particle preparations comparable to those from other plant sources in regard to oxidative activity and requirements. The most active preparations were obtained by blending rather than using a mortar and by washing the particles with the BSA medium. Succinate was readily oxidized while other tricarboxylic acid cycle intermediates were utilized at slower rates.