Accession Number : ADA302665

Title :   The Effect of Triton X-100 on Purple Membrane as Measured by Changes in the Dynamics.

Descriptive Note : Rept. for 1 Feb 87-31 Jan 91,

Corporate Author : VANDERBILT UNIV NASHVILLE TN DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Czege, Jozsef ; Reinisch, Lou

PDF Url : ADA302665

Report Date : 31 JAN 1992

Pagination or Media Count : 28

Abstract : We have observed the light scattering transients arising from changes in the curvature of purple membrane fragments upon photoexcitation at p11 8.05 and 4.1 with and without treatment of Triton X-100. The low ionic strength room temperature suspensions are excited with 532 nm light pulses from a Nd:YAG laser (20 ns). The scattering of 320 nm light is monitored from 3 us to 1 S at scattering angles from 150 to 600. We simultaneously measure the transient transmission changes at 320 nm. The transient light scattering signals change significantly with the addition of 0.02% Triton X-100 at pll 8.05 and 0.006% Triton X-100 at pH 4.1. At these concentrations of Triton we observe maximal amplitudes in the transient changes of the scattered light intensity. At higher concentrations, the Triton solubilizes the protein and the scattering signals are completely attenuated. The transient transmission changes become severely distorted by the scattering changes in the Triton treated samples. We can explain these changes using our bent membrane model and assuming a greater initial curvature and an increased transient curvature change in the membrane fragments after the Triton X-100 is added. The amplitudes of the scattering changes as a function of the scattering angle from 150 to 600 agree with model calculations of the scattering amplitudes.

Descriptors :   *YAG LASERS, *TRANSIENTS, *LIGHT SCATTERING, *FREE ELECTRON LASERS, *MEMBRANES, *AMPLITUDE, ANGLES, SCATTERING, COMPUTATIONS, MODELS, PROTEINS, INTENSITY, TRANSMITTANCE, CURVATURE, LIGHT PULSES, SIGNALS, CONCENTRATION(COMPOSITION), FRAGMENTS, TRITONS.

Subject Categories : Optics
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE