Use of Antipeptide Antibodies for the Isolation and Study of Membrane Proteins: Part A. Preparation

Integral membrane proteins of physiological importance, such as ion channels, transporters, receptors, and enzymes, are usually minor components of the membrane. This low abundance, coupled with their hydrophobicity and frequent instability in detergent solution, renders them very difficult to purify for detailed investigation. As a consequence, most of our knowledge of these proteins has come from gene cloning, which has yielded the amino acid sequences of a large number of membrane proteins. This information allows the study of the tissue and subcellular distribution of the proteins, their topology in the membrane, and their isolation, using antipeptide antibodies, since antibodies raised against short peptides (10–20 amino acid residues) frequently recognize the corresponding sequence in intact proteins (1 ).