ABSTRACT
The effect of crystallization of hydroxyapatite on the secondary structure of bovine serum albumin (BSA) was studied by circular dichroism spectrum, Fourier transform infrared spectroscopy, derivative, deconvolution and curve-fitting techniques in the present paper. The CD results show that pure bovine serum albumin is composed of 56.8% alpha-helices, 5.8% beta-sheets, 14.1% beta-turns and 23.9% random structures, while the bovine serum albumin in the Ca10(PO4)6(OH)2/bovine serum albumin solution is composed of 25.4% alpha-helices, 25.0% beta-sheets, 20.0% beta-turns and 29.7% random structures. The results of Fourier transform infrared spectroscopy are in good agreement with those from the CD spectra. From these results it can be seen that the percentage of alpha-helix decreased, while that of the beta-sheet increased with the formation of the crystal of hydroxyapatite, and with the reaction time increasing, the percentages of alpha-helix obviously dropped and those of beta-sheet markedly rose. These results showed that alpha-helix transformed into beta-sheet. Furthermore the essence of these changes is discussed.
Subject(s)
Circular Dichroism/methods , Durapatite/chemistry , Serum Albumin, Bovine/analysis , Spectroscopy, Fourier Transform Infrared/methods , Animals , Cattle , Crystallization , Protein Structure, Secondary , Serum Albumin, Bovine/chemistryABSTRACT
Three types of CaCO3 can be synthesized through biomimetic synthesis. In the present work, carboxymethyl-starch, etherified-starch, and phosphate-starch, used as organic matrices, were studied by FTIR. The result shows that the intensity of C-O peaks of the three modified-starchs changed. In addition, the intensity of C-O peaks was weakened or vanished obviously with the increase in time. The action mechanism of the modified-starchs and CaCO3 was briefly discussed.