Chemical Cross-Linking in Biology

by chemical cross-linking tech­ nology has greatly intensified during the past 5 years. A number of excel­ lent, timely, and chemically oriented reviews of the cross-linking literature have appeared (4, 68, 87). Therefore, we have attempted to present a critical evaluation of the principles and strategies that govern the applica­ tion of cross-linking technology to the solutions of biological problems. The use of chemical cross-linking reagents as molecular rulers in the determination of quaternary structure in oligomeric protein complexes in solution and in membranes has enjoyed wide app li cation. Another as­ pect of cross-linking technology is the exploitation of heterobif unctional reagents to identif y ligand-binding components in complex biological sys­ tems. It is often difficult to determine how proteins function in multicompo­ nent, complex systems. The classical biochemical approach of isolation and characterization of protein components does not always reveal tran­ sient interactions or migratory behavior of proteins, which occur in the natural environment