Title of article :
Ca2+- and Al3+-Induced Conformational Transitions of Amyloid Fragment H-Ile-Ile-Gly-Leu-Met-NH2
Author/Authors :
Laczkَ، نويسنده , , Ilona and Vass، نويسنده , , Elemér and Soَs، نويسنده , , Katalin and Varga، نويسنده , , Jَzsef L. and Szلraz، نويسنده , , Sلndor and Hollَsi، نويسنده , , Miklَs and Penke، نويسنده , , Botond، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی 11 سال 1996
Abstract :
The effect of Ca2+and Al3+binding on the conformation of the neurotoxic amyloid fragment H-Ile-Ile-Gly-Leu-Met-NH2[βA(31–35)NH2] was studied in trifluoroethanol solutions and in the presence of liposomes. Comparative circular dichroism and Fourier-transform infrared spectroscopic studies revealed that the peptide forms a specific 1:1 complex with Ca2+which coordinates the polar amide carbonyl groups of the peptide backbone. The results suggest the importance of a folded structure in the complexation of Ca2+. On the contrary, the increasing Al3+concentration causes a gradual shift of the conformational equilibrium toward β-sheet structure reflecting no specific binding site for Al3+. In the presence of liposomes the peptide adopts a conformation similar to that of the Ca2+–peptide complex. The relevance of the stabilization of peptide conformation by Ca2+and liposome binding to the bioactive conformation of βA(31–35)NH2is also discussed.
Keywords :
amyloid peptide , calcium binding , aluminum binding , Conformation
Journal title :
Archives of Biochemistry and Biophysics
Journal title :
Archives of Biochemistry and Biophysics