Some quantitative aspects of the reaction of diazonium compounds with serum albumin

• Published in: Archives of biochemistry and biophysics Vol. 53; no. 2; pp. 411 - 424
• Main Authors: Gelewitz, Edmund W., Riedeman, William L., Klotz, Irving M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.1954
• Subjects: Diazonium Compounds; Humans; Old Medline; Serum Albumin; SERUM ALBUMIN
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1016/0003-9861(54)90422-1

A method has been developed for the quantitative analysis of azo groups in azo-coupled proteins. This procedure has been used in conjunction with conventional methods of arsenic and iodine analyses to determine the fraction of diazonium salt introduced into serum albumin by means of azo linkages. It has been found that far fewer groups are introduced than had been anticipated and that only about a third of these groups are attached to the protein by an azo linkage. Bovine or human serum albumin has been coupled with the diazonium salts of the following compounds: arsanilic acid; sulfanilic acid; p-aminosalicylic acid; 2-nitro-4-aminophenol; iodoaniline; 3-aminophthalic acid; 1,1,1-tri-(β-carboxyethyl)-3′-aminoacetophenone; 5-amino-1, 10-phenanthroline; 5-amino-8-hydroxyquinoline. Lysozyme has been coupled with 3-aminophthalic acid. In all cases the azoproteins have been isolated and analyzed for azo groups.