Individual Amino Acids and Carbohydrate Residues

Chemistry of the Individual Amino Acids and Carbohydrate Residues. 

Sulfur containing amino acids. Ceruloplasmin contains 17—18 methionine residues and 14—15 half-cysteine residues [119, 124). Kasper and Deutsch [124) reported that ceruloplasmin has a single —SH group which is readily alkylated in both holo and apo- forms of the protein, 

Witwicki and Zakrzewski [126) have extended the observation, finding that 

Kasper and Deutsch [124) report 0.9 residues of vahne and 0.3 residues of lysine per molecular weight 160,000. Later Ryden [122), working with proteol5dically unaltered protein observed only a single valine per 134,000 g protein. 

Based on the similarity of the proton titration behavior of apo- and holo-cerulo-plasmin Kasper and Deutsch [124) concluded that carboxyl groups did not coordinate to the copper. 

---