Stability of the C-terminal peptide of CETP mediated through an (i, i + 4) array.
Based on circular dichroism (CD), we have found an essential (i, i + 4) alpha-helix stabilizing array in the C-terminus region for the cholesteryl ester transfer protein (CETP) between histidine 466 and aspartic acid 470. This region apparently corresponds to an amphipathic alpha-helix. The behavior of this peptide in solution in comparison with a mutant peptide (D470N) was also analyzed by dynamic light scattering (DLS). The results showed that alpha-helix stabilization is not due to peptide aggregation. The thermodynamic estimation of stability supports the idea that the phenomenon is carried out through an (i, i + 4) array. The representation of the C-terminal region as an amphipathic alpha-helical peptide shows that lipid-binding activity might be in part due to both the asymmetric polar/non-polar residue distribution and to the presence of an (i, i + 4) array important for helix stability.
Bolaños-García
V M
VM
Depto. de Bioquímica, Universidad Nacional Autónoma de México, D.F. México, Mexico.
Soriano-García
M
M
Mas-Oliva
J
J
D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics; D053480:Cholesterol Ester Transfer Proteins; D002942:Circular Dichroism; D006023:Glycoproteins; D008969:Molecular Sequence Data; D009154:Mutation; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics; D017510:Protein Folding; D013329:Structure-Activity Relationship
D002352:Carrier Proteins; D053480:Cholesterol Ester Transfer Proteins; D006023:Glycoproteins; D010446:Peptide Fragments