Phosphorescence from tryptophan and tryptophan analogs in the solid state

Colin McCaul; Richard D. Ludescher

doi:10.1117/12.307068

1 May 1998 Phosphorescence from tryptophan and tryptophan analogs in the solid state

Colin McCaul, Richard D. Ludescher

Proceedings Volume 3256, Advances in Optical Biophysics; (1998) https://doi.org/10.1117/12.307068
Event: BiOS '98 International Biomedical Optics Symposium, 1998, San Jose, CA, United States

Abstract

Tryptophan phosphorescence provides a long-lived optical signal whose lifetime and quantum yield are sensitive to the local environment of the protein The phosphorescence from tryptophan analogs, however, has not been studied. We report here data on the room temperature phosphorescence of tryptophan, 4-, 5-, and 6-fluorotryptophan, and 5- bromotryptophan embedded in sucrose glasses. The absorption of the analogs was either blue-shifted (4-F-trp), markedly red- shifted (5-F-trp and 5-Br-trp), or not shifted (6-F-trp) with respect to tryptophan. The phosphorescence emission spectra of all analogs were red-shifted compared to trp (442 nm) with maxima at 446 nm (5-F), 451 nm (6-F), 452 nm (5-Br), and 469 nm (4-F). The 5-F and 6-F analogs had emission intensities similar to tryptophan (relative quantum yields of 0.68 and 0.91, respectively), while the emission intensities of the 4-F and 5-Br analogs were much lower (relative quantum yields of 0.039 and 0.022, respectively). All analogs exhibited complex decay behavior which required several exponentials for an adequate fit. The average lifetimes were all significantly lower than that of trp (2109 ms). The average lifetimes of the fluorinated analogs (5-F: 1496 ms, 6-F: 1004 ms, and 4-F: 87 ms) scaled approximately with the relative quantum yields while that of 5-Br (1.03 ms) was significantly lower.

Citation Download Citation

Colin McCaul and Richard D. Ludescher "Phosphorescence from tryptophan and tryptophan analogs in the solid state", Proc. SPIE 3256, Advances in Optical Biophysics, (1 May 1998); https://doi.org/10.1117/12.307068

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