SECONDARY STRUCTURE OF T4 GENE-33 PROTEIN FOURIER-TRANSFORM INFRARED AND CIRCULAR DICHROIC SPECTROSCOPIC STUDIES

The secondary structure of bacteriophage T4 gene 33 protein (gp33) has been quantitatively examined by using Fourier transform infrared (FT- IR) and circular dichroism (CD) spectroscopy. Resolution enhancement t echniques, including Fourier deconvolution and derivative spectroscopy were used to quantitate the spectral information from the amide I ban ds. The relative areas of these component bands indicate 21% alpha-hel ix, 25% beta-sheet, 34% turn, 12% random coil and 8% other undefined s tructures in gp33. An analysis of the CD spectrum of gp33 at the same pH and temperature revealed 19% alpha-helix, 25% beta-sheet, 13% turn and 43% random coil structures. The possible reasons for the discrepan cies in estimates of the contributions to the secondary structure from turns and random coils are discussed. (C) 1997 Elsevier Science B.V.