Surface plasmon resonance aptasensing and computational analysis of Staphylococcus aureus IsdA surface protein

AbstractStaphylococcus aureus (S. aureus), a common foodborne pathogen, poses significant public health challenges due to its association with various infectious diseases. A key player in its pathogenicity, which is the IsdA protein, is an essential virulence factor inS. aureus infections. In this work, we present an integrated in-silico and experimental approach using MD simulations and surface plasmon resonance (SPR)-based aptasensing measurements to investigateS. aureus biorecognition via IsdA surface protein binding. SPR, a powerful real-time and label-free technique, was utilized to characterize interaction dynamics between the aptamer and IsdA protein, and MD simulations was used to characterize the stable and dynamic binding regions. By characterizing and optimizing pivotal parameters such as aptamer concentration and buffer conditions, we determined the aptamer's binding performance. Under optimal conditions of pH  7.4 and 150 mM NaCl concentration, the kinetic parameters were determined;ka = 3.789 × 104/Ms,kd = 1.798 × 103/s, andKD = 4.745 × 10−8 M. The simulations revealed regions of interest in the IsdA-aptamer complex. Region I, which includes interactions between amino acid residues H106 and R107 and nucleotide residues 9G, 10U, 11G and 12U of the aptamer, had the strongest interaction, based on ΔG and B-factor values, and hence cont ributed the most to the stability of the interaction. Region II, which covers residue 37A refle...
Source: Biotechnology Progress - Category: Biotechnology Authors: Tags: RESEARCH ARTICLE Source Type: research