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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: vera on September 05, 2008, 07:34:54 PM

Title: fluorescence
Post by: vera on September 05, 2008, 07:34:54 PM

Emission spectra of tryptophan (Trp) in heated and non-heated model system was recorded at lambda (em) = 300-400 nm, lambda (ex) = 290 nm; and maximum intensity was observed at 340 nm.

Then excitation spectra was recorded at lambda (ex) = 250-320 nm, lambda (em) = 340 nm; and maximum intensity was observed at 280 nm.

We can see lower intensity in emission and excitation spectra in heated model system.

But the question is:
What else we can see from described emission and excitation spectra of Trp ? What kind of information ?

Thanks in advance !

Title: Re: fluorescence
Post by: enahs on September 05, 2008, 07:54:21 PM

What part of the molecule of Tryptophan is likely to cause fluorescence?
Why?
What happens when you heat it?

Title: Re: fluorescence
Post by: vera on September 05, 2008, 09:15:30 PM

Tryptophan fluorescence is used as a tool to monitor changes in proteins i.e. protein denaturation caused by heat treatment. Due to protein denaturation i.e. structural changes, tryptophan fluorescence quenching.

Title: Re: fluorescence
Post by: enahs on September 06, 2008, 08:05:00 PM

http://dwb.unl.edu/Teacher/NSF/C08/C08Links/pps99.cryst.bbk.ac.uk/projects/gmocz/fluor.htm

Title: Re: fluorescence
Post by: vera on September 08, 2008, 04:33:59 AM

Enahs, thanks a lot for the link !