Labeling and Isolation of Plasma Membranes from Corn Leaf Protoplasts

Abstract
A plasma membrane-enriched fraction has been isolated from corn leaf mesophyll protoplasts and its identity confirmed with the aid of an external label, diazotized [125I]iodosulfanilic acid. Gentle cell disruption enabled internal organelles to be maintained intact and thus facilitated separation from the plasma membrane. The plasma membrane-enriched fraction was devoid of chloroplast or mitochondrial markers, whereas markers for the endoplasmic reticulum and golgi indicated minimal contamination. The highly enriched plasma membrane fraction contained a Mg2+-dependent, K+-stimulated ATPase with a pH optimum near neutrality. The position of the membranes on sucrose density gradients indicates that the plasma membranes have characteristics similar to other plasma membrane fractions.
Keywords

This publication has 15 references indexed in Scilit: