Transferrins BT - Metalloproteins: Part 2: Metal Proteins with Non-redox Roles

Abstract

Transferrin is a serum β-globulin with the property of reversibly binding iron. It was originally isolated by Schade and Caroline (1946), although its existence had been inferred from earlier studies which had demonstrated that a small amount of the iron in blood was associated with the plasma protein fraction (Fontes and Thivolle, 1925). There are two other proteins which resemble transferrin in many of their properties: ovotransferrin, present in avian egg white and first isolated by Alderton et al. (1946), and lactoferrin, originally isolated from milk by Johansson et al. (1958). This review will deal with the properties and function of all three proteins, and in addition will mention briefly a few other iron-binding proteins which share some affinity with transferrin. Emphasis will be on molecular aspects of structure and function, and the chapter will deal only briefly with synthesis, catabolism, genetic polymorphism and clinical aspects of the transferrins, which are described in more detail in the comprehensive review by Morgan (1981a). Other recent reviews dealing with the structure and function of transferrin are those by Aisen (1980), Aisen and Listowsky (1980) and Chasteen (1983a), and the properties of the transferrins in the wider context of iron metabolism are dealt with by Bezkorovainy (1980).