Study of protein topography with flash photolytically generated nonspecific surface-labeling reagents: surface labeling of ribonuclease A.
RR Matheson, HE Van Wart, AW Burgess, LI Weinstein, HA Scheraga
Biochemistry | Published : 1977
A method for nonspecifically labeling essentially all exposed residues of a protein is described. A reactive aryl nitrene is generated from N-(4-azido-2-nitrophenyl)-2-aminoethylsulfonate (NAP-Taurine), within 500 mus by flash photolysis in the presence of protein. The reactive nitrene is inserted in about 2 ms into those carbon-hydrogen bonds of the protein that are exposed to the solvent. The method is applied here to ribonuclease A to demonstrate the different degree of labeling of the native and denatured protein. On the basis of amino acid analysis, it appears that residues of the native protein that are buried in the interior of the molecule (as judged from the x-ray structure) do not ..View full abstract