Crystal anatomy of the Tag antibody single-chain fragment complexed to its antigen
The clear anatomy of a aberrant anatomy of the single-chain fragment (scFv), acquired from the monoclonal Tag antibody, in circuitous with a hexahistidine peptide has been bent at 2.7 A resolution. The peptide binds to a abysmal abridged formed at the interface of the capricious domains of the ablaze and the abundant chain, mainly through berserk alternation to ambrosial residues and hydrogen bonds to acerb residues.
The antibiotic recognizes the C-terminal carboxylate accumulation of the peptide as able-bodied as the capital alternation of the endure four residues and the endure three imidazole side-chains. The crystals accept a bread-and-butter agreeable of 77% (v/v) and anatomy 70 A-wide channels that would acquiesce the circulation of peptides or even baby proteins. The anti-His scFv crystals could appropriately act as a framework for the condensate of Tag antibody proteins.
Designed mutations in framework regions of the scFv advance to high-level announcement of acrid protein in the periplasm of Escherichia coli. The recombinant anti-His scFv is a acceptable apprehension apparatus if alloyed to acrid phosphatase. If anchored on a matrix, the antibiotic can be acclimated for affection ablution of recombinant proteins accustomed a Tag antibody of just three histidine residues, acceptable for crystallization. The beginning anatomy is now the base for the architecture of antibodies with even college adherence and affinity.