Single-Molecule Recognition and Manipulation Studied by Scanning Probe Microscopy

Dr. Byung Kim, PhD
Department of Physics
Boise State University

Professor Kim conducts single-molecule biomolecular research using scanning probe microscopy (SPM) techniques.
The first part of the talk will focus on chiral recognition, a fundamental aspect of chemical biology that is of central importance in pharmaceutics. Enantiomeric drugs are used to increase the chances of success in targeting enzymes, hormones, and receptors on cell surfaces, along with other compounds that are made up of chiral amino acids, carbohydrates, and lipids. Single-molecule STM images allow us to understand the fundamental mechanism of the chiral recognition of PVBA on Ag(111), but not on Pd(111)1.

The second part of the talk will discuss the binding mechanism between 5’-methylthioadenosine/S-adenosylhomocysteine nucleo-sidase (MTAN) and homocystinyl immucillin A (HIA), the latter being a known inhibitor of MTAN.  The importance of MTAN lies in its uniqueness as a player in the methionine salvage pathway of certain bacteria and its absence of in the pathway of mammals.  Such a feature makes it a potential antibiotic target.

The third part of the talk involves controlling the adsorption and desorption of proteins reversibly using a thermally switchable bioactive surface for future drug delivery 2. At room temperature, a polymer PNIPAM(poly n-isopropyl acrylamide) tethered to a solid surface creates a layer of ordered water around each polymer chain,  inhibiting protein adsorption. Above the transition temperature, however, the water ordering is thermally disrupted, allowing protein adsorption.

References:
1. B.I. Kim, “Chiral Recognition of PVBA on Ag(111) and Pd(111)”, Langmuir (accepted)
2. D. L. Huber, R. P. Maginell, M. A. Samara, B.-I. Kim, and B. C. Bunker, “Programmed Adsorption and Release of Proteins in a Microfluidic Device”, Science 301, 352(2003).