Methods of analyzing cell membranes

Abstract

A method of precipitating cell membrane fragments from a cell lysate is disclosed. The method comprises contacting the cell lysate with a hydrophobic chelator and a metal ion under conditions that allow precipitation of the cell membrane fragments. Kits for precipitating cell membrane fragments are also disclosed.

What is claimed is: 
     
         1 . A method of purifying a membrane protein comprising:
 (a) contacting fragments of a cell membrane which comprises the membrane protein with a hydrophobic chelator and metal ions to generate a complex which comprises said fragments of the cell membrane, said hydrophobic chelator and said metal ions;   (b) isolating said cell membrane fragments following said precipitating; and   (c) solubilizing said membrane protein, thereby purifying the membrane protein.   
     
     
         2 . The method of  claim 1 , wherein said fragments have a length ranging between 200-700 nm. 
     
     
         3 . The method of  claim 1 , wherein said solubilizing is effected using a detergent. 
     
     
         4 . The method of  claim 3 , wherein said detergent is a non-ionic detergent. 
     
     
         5 . The method of  claim 3 , wherein said detergent is selected from the group consisting of decyl β-D-maltoside (DM), dodecyl β-D-maltoside (DDM), octyl β-D-glucoside (OG) and octyl  62  -D-1-thioglucoside (OTG). 
     
     
         6 . The method of  claim 1 , wherein said isolating comprises:
 (a) centrifuging said cell lysate to form a pellet comprising said cell membrane fragments and a supernatant; and   (b) removing said supernatant from said pellet.   
     
     
         7 . The method of  claim 1 , wherein the membrane protein is a retinyledene protein. 
     
     
         8 . The method of  claim 7 , wherein said retinyledene protein is selected from the group consisting of channelrhodopsin, bacteriorhodopsin, halorhodopsin, and proteorhodopsin. 
     
     
         9 . The method of  claim 8 , wherein said retinyledene protein comprises halorhodopsin. 
     
     
         10 . The method of  claim 9 , wherein said halorhodopsin is derived from  Natronomonas pharaonis.    
     
     
         11 . A composition of matter comprising a N-(1,10-Phenanthrolin-5-yl)alkylamide), wherein the alkyl is from 1-9 carbon atoms in length. 
     
     
         12 . The composition of matter of  claim 11 , wherein said N-(1,10-Phenanthrolin-5-yl)alkylamide) is selected from N-(1,10-Phenanthrolin-5-yl)methanamide) (Phen-C1), N-(1,10-Phenanthrolin-5-yl)ethanamide) (Phen-C2), N-(1,10-Phenanthrolin-5-yl)propanamide) (Phen-C3), N-(1,10-Phenanthrolin-5-yl)butanamide) (Phen-C4), N-(1,10-Phenanthrolin-5-yl)pentanamide) (Phen-C5), N-(1,10-Phenanthrolin-5-yl)hexanamide) (Phen-C6), N-(1,10-Phenanthrolin-5-yl)heptanamide) (Phen-C7), N-(1,10-Phenanthrolin-5-yl)octanamide) (Phen-C8), and N-(1,10-Phenanthrolin-5-yl)nonanamide) (Phen-C9).