Native fluorescence of proteins as a real time monitor of the inactivation of ricin and model enzymes by disinfectants

ANYL 465

Adolfas K. Gaigalas, adolfas.gaigalas@nist.gov, Kenneth D. Cole, Kenneth.Cole@nist.gov, and Jamie Almeida, jamie.almeida@nist.gov. Biochemical Science Division, National Institute of Standards and Technology, 100 Bureau Dr, Stop 8312, Gaithersburg, MD 20899
Measurement of native protein fluorescence due to tryptophan and tyrosine residues was investigated as a sensitive and non-invasive method to monitor the modification and inactivation of protein toxins by common disinfectants (bleach and monochloramine). The biological activity of ricin and two model enzymes (chicken egg lysozyme and bovine heart lactate dehyrogenase) was measured with time in different concentrations of the disinfectants. Fluorescence intensity of the same samples was also measured. The kinetics of the inactivation of the three proteins was correlated with the loss of fluorescence intensity indicating the destruction of the tryptophan and tyrosine residues. Fluorescence and absorbance measurements were also done using N-acetyl tryptophan and N-acetyl tyrosine to compare the reactions of the isolated amino acids in solution. We will discuss the location of the aromatic amino acids in this proteins based on their three dimensional structure and correlation with loss of activity due to the action of the disinfectants.
 

Analytical Approaches
1:30 PM-4:30 PM, Thursday, August 23, 2007 BCEC -- 104A, Oral

Division of Analytical Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007