Date of Award
Bachelor of Science
Fluorescence quenching data have been collected on several small peptides (1-4) residues which contain tryptophan. These data have been analyzed by a variety of methods. The classical Stern-Volmer equation is utilized to obtain Stern-Volmer plots of fluorescence quenching data. Substantial upward curvature is observed in the Stern-Volmer plots of all the peptides studied. Data were also analyzed via the modified Stern-Volmer static quenching model. Although this model could explain the deviation from simple Stern-Volmer behavior found in SV plots, the parameters used by the model were often physically “unrealistic”: Therefore, another form of data analysis was used. The newly proposed Peak dynamic quenching model was tested. This model could explain the deviation from simple Stern-Volmer behavior in a physically tangible manner. A value for quenching efficiency E is derived from the Peak model. Finally, charge effects and ionic strength effects on fluorescence quenching are investigated. Some very interesting ionic strength effects have been found in the quenching data of several peptides. In the case of +TGG- vs. acrylamide, there appears to be a cation effect on quenching.
Dennin, Richard, "Fluorescence quenching of peptidyl tryptophan by external quenchers" (1983). Honors Theses. 1888.