Structures Of The Differential Type Spr Instrument For Vancomycin / Antibody Interaction Studies,

Surface Plasmon Resonance is a new instrumental method forstudying biomolecular interactions at the metal/solution interface. It iswidely applied to investigating biomolecular interactions for itssensitivity to the refraction index change of the medium near a thin filmof metal deposited on a glass substrate, which make it is very sensitiveand label free. In this work, a home made high-resolution FI-SPR wasused in detecting the interactions between the Vancomycin and Antibody.In this work, a self-built high resolution FI-SPR setup was made.The incorporation of a bi-cell photodiode detector improved thesensitivity of SPR (angular resolution: 10^-4～10^-5 degree). Furthermore, theinfluence of the mechanical vibrations, thermal drift, and theenvironmental noise were avoided by using a optical platform and ashock mounting. Coupled with a Flow Injection device and a home-madeflow cell (internal volume:～4μL), the FI-SPR instrument is capable ofmeasuring the biomolecular interactions in situ, highthroughout, andmore sensitively.Vancomycin is an antibiotic that inhibits the cell wall biosynthesis ofgram- positive bacteria by specifically binding to cell wall peptidoglycansthat terminate in D-Ala-D-Ala, resulting in bacteriostasis or bacterial celldeath. Thereby it is important for the bacteria resistant investigation ofvancomycin to discover the interaction mechanism. In this workVancomycin was immobilized to the surface of Au film by using LBLtechnique. AE was employed to avoid the influence of the nonspecificadsorption between multi-peptide ligand and surface of Au film. A detectlimit for multi-peptide antibody as low as 500nmol·L^-1 (7.5×10¹²mol)was achieved, which is lower than that obtained by others. A goodlinearity was gained between 0.5μmol·L^-1～100μmol·L^-1. Non-linearfitting method was employed to evaluate the binding constants (k_d=3.95×10^-3 s^-1, k_a=1.74×10³ mol^-1·L·s^-1).