Transferrins functional aspects

A potentially confusing aspect of transferrin structure and function is that, prior to determination of the lactoferrin and transferrin structures, the N- and C-terminal halves of each molecule were often referred to as N- and C-domains. Given the clear subdivisions apparent in Fig. 4, however, the commonly accepted definition of protein domains (separately folded units see Ref. 83), and the functional importance of these units, it seems preferable to think of the transferrins as proteins comprising two lobes, but four domains. 

Transferrin binds the iron as an Fe center with a coordinating bicarbonate anion thought to be a necessary adjunct. It is possible that this bicarbonate has a buffer function on release of the iron in the form of iron(II). The considerations presented in Section 8.7.4.3 on iron redox chemistry and core formation examine such aspects in greater depth. The uptake is probably via receptor-mediated endocytosis and the majority view is now that ferroxidase activity is the next step in the uptake process with the overall process being an oxidative one starting from Fe. ... 

This process includes dietary, anthropometric, and biochemical aspects. Nutritional assessment begins with a detailed nutritional history that includes clinical, dietary, socioeconomic, and family issues. Areas of interest include present and past illnesses, family illness history, food allergies or intolerance, medications, nutritional supplements, over-the-counter medications, alcohol use, work environment, and education level. A useful standardized protocol is the Prognostic Nutritional Index (PNI), which incorporates serum albumin, serum transferrin, delayed skin hypersensitivity, and triceps skinfold thickness (20,21). The PNI has been shown to correlate with postoperative complications and mortality (22). Whole body functional assessment by examining overall activity, exercise tolerance, grip strength, respiratory function, wound healing, and plasma albumin concentration can also be useful. 

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