Classification: Primary Faculty

Education: Ph.D., 1993, University of Amsterdam

Fields of Study: 

• Atomic, Molecular, and Optical Physics
• Biological Physics
• Condensed Matter Physics

Research Interests: 

Optical tweezers are ideally suited for probing the effects of force upon biological processes. I have previously pioneered the so-called optical force clamp, a feedback-controlled optical tweezers, which maintains a constant force upon a single moving motor protein (Visscher et al., Nature 400, 184-189). While at the University of Arizona our research has focused on the role of mechanical force in the regulation of gene-expression. We not only investigate how tension in DNA controls initiation of transcription by T7 RNA polymerases, but also how it affects the translocation of ribosomes along mRNA, and how force unfolds downstream mRNA structures known to cause translational recoding (-1 frameshifting, -1 FS).

Selected Publications: 

White, K.H. & Visscher, K. Optical Trapping and unfolding of RNA. Meth. Mol. Biol. 783, 21-43 (2011).

White, K.H., Orzechowski, M., Fourmy, D. & Visscher, K. Mechanical unfolding of the Beet Western Yellow Virus -1 frameshift signal. JACS 133, 9775-9782 (2011).

Skinner, G.M, Kalafut B., & Visscher, K. Downstream DNA tension regulates the stability of the T7 RNA polymerase initiation complex. Biophysical Journal 100, 1034-1041 (2011).

Visscher K., Schnitzer M.J., and Block S.M., "Single kinesin molecules studied with a molecular force clamp." Nature 400, 184-189 (1999). Featured in Nature Cell Biology News&Views: Knight A.E., and Molloy J.E., "Coupling ATP hydrolysis to mechanical work.", Nature Cell Biology 1, E87-E89 (1999).

Mueller M., Ghauhalari R., Visscher K., and Brakenhoff G.J., "Double-pulse fluorescence lifetime imaging in confocal microscopy.", J. Micr. 177, 171-179 (1995).