Macromolecular Interactions Core Laboratory (MICL)

Biotech Place

Roy R. Hantgan, PhD, Director

Mary C. Stahle, Research Technician III

Contact: rhantgan@wfubmc.edu TEL: 336-716-4675

MICL provides instrumentation and expertise to enable investigators to detect and measure interactions between biological macromolecules using an array of biotechnologies: surface plasmon resonance spectroscopy (SPR), fluorescence spectroscopy, circular dichroism spectroscopy, light scattering, and analytical ultracentrifugation.

Instrumentation:

SPR: Measurements of the rate and extent of reversible complex formation between two macromolecules, one immobilized on a biosensor chip and the other delivered by microfluidics, can be performed with a Biacore T100 high-performance research instrument. This system integrates SPR biosensor technology with robotic control of coupling chemistry, analyte delivery, signal acquisition and data processing. The Biacore T100 also provides precise temperature control and powerful data reduction algorithms enabling the acquisition and analysis of real-time kinetic data. Typical applications include measuring the on- and off-rates and equilibrium constants for receptor:ligand, antigen:antibody, protein:nucleic acid, or protein:lipid interactions.

Fluorescence Spectroscopy: Excitation and emission scans, fluorescence lifetime, and anisotropy measurements can be performed on an ISS K2 Multifrequency Phase Modulation Fluorometer equipped with a Xenon-Hg arc lamp and an argon ion laser. Typical applications include fluorescence anisotropy measurements of the rate and extent of interactions between a fluorophore-tagged ligand or oligonucleotide and a receptor or DNA binding protein.

Circular Dichroism Spectroscopy: CD measurements of macromolecular secondary structure can be performed on a JASCO Model 720A Spectropolarimeter. Typical applications include comparing the solution conformation of a wild-type protein and a series of single-site mutants or measuring denaturant-induced unfolding of a macromolecule.

Light Scattering: Classical (static) and dynamic light scattering measurements can be performed with a Brookhaven Instruments system built around a BI-2030 AT digital correlator, a BI-200 SM motorized goniometer (for angular-dependent, photon-counting data collection). Light sources include both a 10W argon ion laser (Coherent INNOVA 300) and a 35 mW He-Ne laser (Spectra Physics Model 127). Typical applications include characterizing the oligomeric state of a macromolecule and determining the size distributions of lipid vesicle preparations.

Analytical Ultracentrifugation: Sedimentation velocity and equilibrium measurements can be performed with a Beckman XLA analytical ultracentrifuge housed in the WFU Center for Structural Biology, housed in the Bowman Gray Technical Center. Typical applications include characterizing the size, shape and oligomeric state of macromolecules.

MICL Policies: Investigators are encouraged to work with our staff to design, carry out, and interpret pilot experiments designed to test the feasibility of an in-depth investigation. Facility charges for instrument use and investigator training apply to subsequent studies. While limited information can be obtained on a fee-for-service basis, investigators are encouraged to consider collaborative arrangements as most studies will not be turn-key but require our expertise.