title: Nitrite-assisted peptide iodination and conjugation.
abstract: In this study, a simple method for selective iodination of peptides and proteins is established. Using angiotensin II as the model system, we demonstrate that nitrite catalyzed the selective iodination of the peptide at the N-terminus in an acidic solution. The N-terminal-iodinated peptides alkylated thiol-containing molecules such as N-acetylcysteine and glutathione to form peptide conjugates in a basic solution. Reactive species formed by increasing the pH of the reaction mixture of sodium nitrite and sodium iodide from 4 to 8 selectively iodinated peptides and proteins at tyrosine and histidine residues. These results show that nitrite is a useful catalyst for peptide and protein ligation.
authors.affiliation: The Proteomics Resource Center, The Rockefeller University, NY 10021, New York, USA. dengh@rockefeller.edu
authors.forename: Haiteng
authors.initials: H
authors.lastname: Deng
mesh_terms: D000804:Angiotensin II / Q000737:chemistry; D000818:Animals; D002417:Cattle; D045304:Cytochromes c / Q000138:chemical synthesis / Q000737:chemistry; D006639:Histidine; D007202:Indicators and Reagents; D007328:Insulin / Q000138:chemical synthesis / Q000737:chemistry; D007455:Iodine; D013058:Mass Spectrometry; D009206:Myocardium / Q000201:enzymology; D009573:Nitrites; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry*; D014443:Tyrosine
chemical_list: D007202:Indicators and Reagents; D007328:Insulin; D009573:Nitrites; D010455:Peptides; D000804:Angiotensin II; D014443:Tyrosine; D006639:Histidine; D045304:Cytochromes c; D007455:Iodine