Secondary structure of holo- and apo-aminoacylase from prediction, circular dichroism, and FT-Raman spectroscopy.
The secondary structures of native (Holo-) and Zn(2+)-free (Apo-) aminoacylase were examined by circular dichroism (CD) and Fourier transform Raman (FT-Raman) spectroscopic techniques and prediction methods. Quantitative analysis of the conformationally sensitive amide I band indicates that Holo- and Apo-enzyme contain 19.3 and 17.2% helical structure, respectively. Far-UV CD spectra of Holo- and Apo-enzyme show that they contain 20.1 and 17.6% alpha-helix, respectively. Secondary structure prediction of aminoacylase indicates that it contains approximately 20.9% alpha-helical structure including 10 alpha-helix segments. The results show that after removal of Zn2+ in aminoacylase, the extent of ordered structure was decreased markedly. The conformation at or near the active site of aminoacylase may contain more ordered structure and the presence of Zn2+ may help to maintain the catalytically active conformation at the active site.
Tang
Z Y
ZY
Department of Biological Science & Biotechnology, Tsinghua University, Beijing, P.R. China.
Yu
J Y
JY
Zhou
Q
Q
He
B
B
Wang
Z F
ZF
Zhou
H M
HM
D000581:Amidohydrolases / Q000737:chemistry*; D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D003198:Computer Simulation; D007668:Kidney / Q000201:enzymology; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D013059:Spectrum Analysis, Raman; D013552:Swine
D000581:Amidohydrolases; C019672:aminoacylase I