Apotransferrin proton dissociation and interactions with hydrogencarbonate in neutral media

✍ Scribed by Louisa Bellounis; Rowchanak Pakdaman; Jean Michel El Hage Chahine

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 594 KB
• Volume: 9
• Category: Article
• ISSN: 0894-3230
• DOI: 10.1002/(sici)1099-1395(199602)9:2<111::aid-poc761>3.0.co;2-4

✦ Synopsis

A spectrofluorimetric titration analysis of the proton dissociation and the interactions of human serum transferrin with hydrogencarbonate was performed at pH 7-0-9.0. Apotransferrin loses a single proton probably per binding site with K , = (6.80i0.35) x M. This proton dissociation is independent of the hydrogencarbonate concentration. Apotransferrin does not interact with CO,'-. However, it interacts with two HCO,-, exhibiting two different affinity constants; the dissociation constant presumably for the C-site is K, = (4.4OrtO-15) x M and that for presumably the N-site is K , = (3.60i0.30) x lo-' M. These interactions