title: The secondary structure analysis of a potent Ser14Gly analog of antiAlzheimer peptide, Humanin, by circular dichroism.
abstract: The structure of a highly potent Ser14Gly analog of antiAlzheimer peptide, Humanin, was examined by circular dichroism (CD). The secondary structure is more disordered in water than in phosphate-buffered saline (PBS). The peptide structure in water is little dependent on both peptide concentration and temperature. On the contrary, the peptide structure was significantly different in PBS from the structure in water, which is more apparent at a higher peptide concentration and temperature. The observed different structure in PBS appears to be due to self-association of the peptide, which is enhanced by elevated temperature and, hence, via hydrophobic interactions. The wild-type Humanin also behaved similarly, i.e., it assumed a disordered structure in water but underwent conformational changes in PBS. Although high peptide concentrations for CD measurements are not encountered in vivo, the results suggest the tendency of the peptide to interact hydrophobically with other structures as well as with itself.
authors.affiliation: Alliance Protein Laboratories, Thousand Oaks, CA 91360, USA. tarakawa2@aol.com
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arakawa
authors.forename: Takako
authors.initials: T
authors.lastname: Niikura
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Tajima
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Kita
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy; D002942:Circular Dichroism; D005998:Glycine / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D009154:Mutation; D017433:Protein Structure, Secondary; D012694:Serine / Q000737:chemistry; D012995:Solubility; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C427211:humanin; D012694:Serine; D005998:Glycine