Amino acid sequences within the alpha subunit of Integrin alpha (sub m)Beta (sub 2) (Mac-1) critical for specific recognition of C3bi

The interaction of opsonized particles with neutrophils and monocytes is influenced by the level of reaction that takes place between the receptor and the major integrins of neutrophils. A binding assay performed on 293 human kidney cells proved that the C3bi binding pocket of amino acids are composed of the P147-R152, P201-K217 and K245-R261 regions, which are all instrumental in facilitating the alpha (sub m)beta (sub 2) binding. It was also shown the formation of this bond may be hindered by induction of conformational changes or direct competition for the ligand binding site.