Resonance Raman and Fourier transform infrared spectroscopic studies of the acyl carbonyl group in [3-(5-methyl-2-thienyl)acryloyl]chymotrypsin: evidence for artifacts in the spectra obtained by both techniques.

The acyl carbonyl group of [3-(5-methyl-2-thienyl)acryloyl]chymotrypsin (5MeTA-chymotrypsin) has been investigated by using both resonance Raman (RR) and Fourier transform infrared (FTIR) spectroscopies. The spectrum of the acyl-enzyme carbonyl group has been obtained as a function of pH over the range 3.0-10.0 in the RR experiments and over the range 3.4-7.6 (p 2 H) in the FTIR experiments