In:
International Journal of Protein Research, Wiley, Vol. 2, No. 1-4 ( 1970-12), p. 247-256
Kurzfassung:
The possibility of mapping the topography of proteins in solution by irradiation of protein‐sensitizer complexes has been tested using some nitrophenyl derivatives of ribonuclease A as models. In the case of N e ‐41′‐dinitrophenyl‐ribonuclease A, we achieved the specific modification of methionine‐30, histidine‐12, and tyrosine‐97: the side chains of these amino acid residues appear to be located less than 5 A apart from the e.‐amino group of lysine‐41; on the other hand, histidine‐119, which is more than 5 A away, was not affected. These findings are in excellent agreement with the X‐ray model of ribonuclease A. The reliability and the high stereospecificity of this procedure was further demonstrated by irradiation of ribonuclease A, which had been labeled by the dinitropheny! chromophore at the cysteinyl residues 65 and 72: in this case, there was a preferential photo‐oxidation of two tyrosyl residues, probably tyrosine‐73 and tyrosine‐115, adjacent to the labeling groups, which appear to be projected towards the inner regions of the protein molecule. On the contrary, on irradiation of ribonuclease A, after nitration of the three exposed tyrosines, the nitrophenol chromophores, which lacked any preferred orientation, induced a simultaneous random modification of the potentially photo‐oxidizable amino acids. It appears, therefore, that this method yields quite reliable and refined information about the tertiary structure of proteins, provided that the introduced sensitizer is inserted in fixed positions within the protein matrix.
Materialart:
Online-Ressource
ISSN:
0020-7551
DOI:
10.1111/jpp.1970.2.issue-1-4
DOI:
10.1111/j.1399-3011.1970.tb01682.x
Sprache:
Englisch
Verlag:
Wiley
Publikationsdatum:
1970
