Enzymes associated with protein bodies isolated from ungerminated barley seeds

Abstract

Protein bodies were isolated intact from dormant barley seeds, Hordeum vulgare, var. Kenia, by a combination of buffer extractions and centrifugations over a sucrose gradient. Examination of the protein bodies pellet in the electron microscope shows 2 types of protein bodies in a wide variation of sizes. The majority of them stain evenly with osmium, are contained within a single membrane, and have no other structural components. The other type, mostly the larger particles, has a fine structure of orderly dark and light-stained layers attached to the protein bodies. Two acid hydrolases are associated with these particles: acid phosphatase activity, specific for sodium phytate but inactive on beta-glycerol phosphate, glucose 1-phosphate, fructose 1,6-diphosphate and adenosine triphosphate; and acid protease activity.