FTIR spectroscopy, a useful tool for selecting precipitating agents in the fractionation of proteolytic enzymes

CRISTINA BARCIA.; GERARDO CAMÍ.; SONIA BARBERIS

Buenos Aires

Workshop; International Workshop on Infrared Spectroscopy Applied to Biological and Biomimetic Systems: From the Isolated Molecule to the Cell.; 2007

Buenos Aires, Argentina.

FTIR spectroscopy has been used in the study of the secondary structure of numerous proteins with no restriction on their molecular mass (1-4). The aim of this work was to carry out a comparative study of the secondary structure of proteolytic enzymes of Acacia caven (Mol.) Molina pollen, in saline solution and after fractionation them with acetone, ethanol, methanol and ammonium sulphate; using FTIR spectroscopy. Fig.1 shows the FTIR spectrum of proteolytic enzyme of Acacia caven pollen in saline solution and after fractionation them with methanol, in the 1700 ? 1600 cm-1 range (amide I band). The maximum intensity of those enzyme in saline solution was found at 1653 cm-1 (random structure) followed in intensity by a band at 1683 cm-1 (-turn structure). The random component, usually referred to as random coil, was defined in early X-ray crystallographic studies as a secondary structure of -helix nor -sheet (5).