title: Modification by simetryn sulphoxide of a specific thiol group in rat haemoglobin.
abstract: Native rat haemoglobins were found to bind simetryn sulphoxide to an extent 40-fold greater than human haemoglobin. This specific behaviour was studied by using only high-pressure ('performance') liquid chromatography for the preparative separation of globin chains and the isolation of peptides resulting from chemical and enzymic degradation. High recoveries (greater than 80%) of peptides throughout the procedures in combination with microsequence techniques, allow a definitive assignment of the residue undergoing modification. The haemoglobin beta-chain cystine-125 residue, with a stoichiometry of one per tetramer of rat haemoglobin, was found to be modified. Stereochemical implications of this finding are discussed. Simetryn sulphoxide would appear to be useful as a specific reagent for the mapping of exposed thiol residues in proteins.
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003488:Cyanogen Bromide; D006454:Hemoglobins / Q000378:metabolism*; D006540:Herbicides; D010455:Peptides / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D011487:Protein Conformation; D051381:Rats; D013438:Sulfhydryl Compounds / Q000032:analysis; D014227:Triazines / Q000494:pharmacology*
chemical_list: D006454:Hemoglobins; D006540:Herbicides; D010455:Peptides; D013438:Sulfhydryl Compounds; D014227:Triazines; C033807:simetryn; C033806:simetryn sulfoxide; D003488:Cyanogen Bromide