Complement binding site

IgG is the lymphokine, IBF (immunoglobulin-binding factor). This has been reported to be a T-cell product which binds the Fc region of IgG close to the complement-binding site (Fridman and Golstein, 1974). Its biologiced significance is unknown. 

Lactoferrin resembles transferrin in terms of molecular weight, amino-acid sequence homology and number of Fe(lII) binding sites. Lactoferrin is released from activated PMNs upon degranulation and may play a role in myelopoiesis, primary antibody response, lymphocyte proliferation, cytokine production and complement activation. 

Methods that utilize structural data of the target, generally identified by protein crystallography, to look for molecules that complement the binding site through favorable protein-ligand interactions (protein structure-based VS or SBVS). 

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