The Extraction of ATPase from Amyloplast Envelope Members of Sycamore

Abstract

The objective of this study is the investigation of suitable detergents for Mg²⁺ -ATPase extraction from the amyloplast envelope membranes of suspension-cultured cells of sycamore (Acer pseudoplatanus L.). Among four types of detergents tested : Triton X-100, octylglucoside, sarkosinate and deoxycholate, it was found that Triton X-100 at the proportion Triton : membrane protein weight = 3:1, is suitable for ATPase-extraction. The solubilizable fraction was applied on sucrose density gradient. After centrifugation, it was found that the fraction with maximum ATPase activity possess a predominant polypeptide of 37-kDa. The result of the autoradiographic technique using adenosine triphosphopyridoxal suggested that the 37-kDa polypeptide may be a subunit of the Mg²⁺-ATPase of amyloplast envelope membranes.