title: Near-ultraviolet difference absorption and circular dichroism studies on partially synthetic ribonucleases S'.
abstract: Near-ultraviolet difference absorption and circular dichroism (CD) spectra were recorded upon recombination of synthetic S-peptide analogs, i.e. 1epsilon, 7epsilon-diguanidino-[Tyr8]-,1epsilon,7epsilon-diguanidono-[Asn14]-, [Phe(F)8, Orn10]- and 1epsilon, 7epsilon-diguanidino-S-peptide, with S-protein. Environmental alterations of Phe-8 in the S-peptide and Tyr-25 in the S-protein, derived from the association process, lead to strong optical signals whose location and magnitude were clearly defined by means of a comparative analysis of the above spectra. Additionally, the spectroscopic effects resulting from insertion of a tyrosyl residue into an hydrophobic environment in the presence or absence of hydrogen-bonding partners were identified and compared with similar findings obtained from the model compound p-cresol.
mesh_terms: D002942:Circular Dichroism; D006146:Guanidines; D009952:Ornithine; D010455:Peptides; D010649:Phenylalanine / Q000031:analogs & derivatives; D011485:Protein Binding; D011487:Protein Conformation; D012260:Ribonucleases; D013056:Spectrophotometry, Ultraviolet
chemical_list: D006146:Guanidines; D010455:Peptides; D010649:Phenylalanine; D009952:Ornithine; D012260:Ribonucleases