Time-resolved fluorescence of thioredoxin single-tryptophan mutants: modeling experimental results with minimum perturbation mapping

Norberto D. Silva Jr.; Christopher Haydock; Franklyn G. Prendergast

doi:10.1117/12.182723

17 August 1994 Time-resolved fluorescence of thioredoxin single-tryptophan mutants: modeling experimental results with minimum perturbation mapping

Norberto D. Silva Jr., Christopher Haydock, Franklyn G. Prendergast

Author Affiliations +

Proceedings Volume 2137, Time-Resolved Laser Spectroscopy in Biochemistry IV; (1994) https://doi.org/10.1117/12.182723
Event: OE/LASE '94, 1994, Los Angeles, CA, United States

Abstract

The time-resolved fluorescence decay of single tryptophan (Trp) proteins is typically described using either a distribution of lifetimes or a sum of two or more exponential terms. A possible interpretation for this fluorescence decay heterogeneity is the existence of different isomeric conformations of Trp about its (chi) +1) and (chi) +2) dihedral angles. Are multiple Trp conformations compatible with the remainder of the protein in its crystallographic configuration or do they require repacking of neighbor side chains? It is conceivable that isomers of the neighbor side chains interconvert slowly on the fluorescence timescale and contribute additional lifetime components to the fluorescence intensity. We have explored this possibility by performing minimum perturbation mapping simulations of Trp 28 and Trp 31 in thioredoxin (TRX) using CHARMm 22. Mappings of Trp 29 and Trp 31 give the TRX Trp residue energy landscape as a function of (chi) +1) and (chi) +2) dihedral angles. Time-resolved fluorescence intensity and anisotropy decay of mutant TRX (W28F and W31F) are measured and interpreted in light of the above simulations. Relevant observables, like order parameters and isomerization rates, can be derived from the minimum perturbation maps and compared with experiment.

Citation Download Citation

Norberto D. Silva Jr., Christopher Haydock, and Franklyn G. Prendergast "Time-resolved fluorescence of thioredoxin single-tryptophan mutants: modeling experimental results with minimum perturbation mapping", Proc. SPIE 2137, Time-Resolved Laser Spectroscopy in Biochemistry IV, (17 August 1994); https://doi.org/10.1117/12.182723

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available