02118naa a2200217 a 450000100080000000500110000800800410001910000240006024501020008426000090018630000210019552013590021665000140157565300250158965300090161465300120162365300240163570000180165970000190167777302040169610269661999-12-22       1996    bl ---       0--  u    #d1 aBERNARDES FILHO, R.  aEvaluation of the quantitatives methods to determine the secondary structure of proteins by FTIR.  c1996  ap.129. Ref.M-56.  aThe quantification of secondary structure from infrared bands is not simple and present serious problems. In this paper, we evaluate the quantitatives aspects of "resolution enhancement" and "pattern recognition" methods. In the first case we studied the Fourier deconvolution technique to enhance the resolution and use a fitting program to resolve the individuals bands. The results show that this method is not adequate to quantify the secondary structures. The major problems are the strong influence of the operator in selecting the parameters to fit the data, the correct assignment of the bands, etc. We have observed up to 50% in error using this method. The pattern recognition technique is based on a partial least squares method. It is necessary to obtain a calibration matrix using the infrared spectra and the proportions of secondary structure from X rays. The user almost does not interfere in the process.The problems are the definition of the types of secondary structures to use (alfa helix, beta sheet, beta turns, etc) and chose the method for calculate them from X rays data bank. We tested Levitt & Greer; Kabsch & Sander, Kabsch & Sander Modified algorithms to calculate secondary structures and the FTIR results show a better correlation when we use alfa helix, beta sheet and undefined structures with Levitt & Greer calculation.  aProteína  aEstrutura secundaria  aFTIR  aProtein  aSecondary structure1 aFORATO, L. A.1 aCOLNAGO, L. A.  tIn: REUNIAO ANUAL DA SOCIEDADE BRASILEIRA DE BIOQUIMICA E BIOLOGIA MOLECULAR, 25., maio 1996, Caxambu, MG. Programa e resumos... [S.l.]: Sociedade Brasileira de Bioquimica e Biologia Molecular, 1996.