Investigation of pH-Induced Protein Conformation Changesby Nanomechanical Deflection.

Broad-spectrum biosensing technologiesexamine sensor signals usingbiomarkers, such as proteins, DNA, antibodies, specific cells, andmacromolecules, based on direct- or indirect-conformational changes.Here, we have investigated the pH-dependent conformational isomerizationof human serum albumin (HSA) using microcantilevers as a sensing platform.Native and denatured proteins were immobilized on cantilever surfacesto understand the effect of pH on conformational changes of the proteinwith respect to the coupling ligand. Our results show that protonationand deprotonation of amino acid residues on proteins play a significantrole in generating charge-induced cantilever deflection. Surface plasmonresonance (SPR) was employed as a complementary technique to validatethe results. [ABSTRACT FROM AUTHOR]