SECONDARY STRUCTURE OF THE PLASMA-MEMBRANE ATPASE OF CORN ROOTS (ZEA-MAIS L) - AN ATTENUATED TOTAL-REFLECTION FTIR SPECTROSCOPY STUDY

The attenuated total reflection ATR-FTIR technique was used to investi gate the secondary structure of the plasma membrane H+-ATPase of corn roots. In order to point out the differences and similarities between the secondary structure of the plasma membrane H+-ATPase of plants and of other P-type ATPases, we have compared the FTIR spectra of the cor n root H+-ATPase to that of the Neurospora crassa plasma membrane H+-A TPase and of the H+/K+-ATPase from the gastric hog. Comparison with th e amide I of the two other beta-ATPase indicates a roughly similar sha pe but with a distinct difference in the region of the beta-sheet, wit h less beta-sheet contribution in the case of the corn roots H+-ATPase but more alpha-helix. It is concluded that significant structural dif ferences may exist within the beta-type ATPase family. (C) 1996 John W iley & Sons, Inc.