BPTI: Molecular Dynamics (300K)

A model of Bacteriorhodopsin

BR photocycle

t [ps]

C13 – C14

C14 – C15

13-14

14-15

NH

H N

Prot.

hν

W. Zinth et. al.

Time-resolved Pump-Probe Spectrum of Sensorhodopsin

W. Zinth et. al.

BR J

J K

hν

FTIR: Spectra from Interferograms

mirror position

IR spectrum of polystyrene

IR amide bands of proteins

Amide I band provides information on secondary structure

Monitoring protein unfolding by FTIR: folded

Monitoring protein unfolding by FTIR: unfolded

Difference FTIR

Fritz Siebert

Time resolved difference FTIR of bacteriorhodopsin

Fritz Siebert

rupture force

cantilever-position x

force

0

250 pN

Single Molecule Force Spectroscopy

E.-L. Florin, V. T. Moy, H. E. Gaub, Science 264, 415 (1994)

rupture force [pN]co

unts

Gautel et al., Science 1997, Biophysical Journal 1999Linke and Fernandez, J. of Muscle and Cell Mot. 2002

Force probe experiments (AFM, opt. tweezer):--> Ig domains as “shock absorbers“