Fluorescence studies with conformationally constrained tryptophan analogs: implications on the mechanisms of intramolecular quenching

Maurice R. Eftink; D. Hu; Y. W. Jia

doi:10.1117/12.58198

1 April 1992 Fluorescence studies with conformationally constrained tryptophan analogs: implications on the mechanisms of intramolecular quenching

Maurice R. Eftink, D. Hu, Y. W. Jia

Author Affiliations +

Proceedings Volume 1640, Time-Resolved Laser Spectroscopy in Biochemistry III; (1992) https://doi.org/10.1117/12.58198
Event: OE/LASE '92, 1992, Los Angeles, CA, United States

Abstract

The fluorescence properties of a set of tryptophan analogs, including several that are conformationally restricted, is reported. The conformationally restricted analogs include tetrahydrocarboline-3-carboxylic acid, 3-amino-3-carboxytetrahydrocarbazole, 3- aminotetrahydrocarbazole, and 3-carboxytetrahydrocarbazole. Steady-state and time-resolved measurements were made. The fluorescence decay of most of the conformationally restricted analogs is a bi-exponential. The fluorescence quantum yield and average lifetime of the restricted analogs is a bi-exponential. The fluorescence quantum yield and average lifetime of the restricted analogs are higher than the values for tryptophan and corresponding flexible tryptophan analogs. This indicates that the effective rate constant for intramolecular non- radiative (quenching) processes, knx, is smaller for the restricted tryptophan analogs than for the flexible analogs. For a series of flexible analogs, having a bifunctional side chain, there is synergism between the two functional groups (i.e., (alpha) -NH3+ and (alpha) -CO2- groups) in determining the effective knx. Potential mechanisms for intramolecular quenching mechanisms, which contribute to knx, include proton transfer from a side chain ammonium group to position four of the excited indole ring and charge transfer from the excited indole ring to a side chain acceptor group. By measuring the rate of photo-induced isotope exchange into position four of an analog's indole ring, we have estimated the contribution of proton transfer quenching to the total intramolecular quenching rate constant for several flexible tryptophan derivatives.

Citation Download Citation

Maurice R. Eftink, D. Hu, and Y. W. Jia "Fluorescence studies with conformationally constrained tryptophan analogs: implications on the mechanisms of intramolecular quenching", Proc. SPIE 1640, Time-Resolved Laser Spectroscopy in Biochemistry III, (1 April 1992); https://doi.org/10.1117/12.58198

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

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
6 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Analog electronics

Luminescence

Quantum efficiency

System on a chip

Biochemistry

Laser spectroscopy

Modulation

Show All Keywords

Keywords/Phrases

Search In:

Publication Years