Kinetics of coil to α-helix to β-structure transitions of poly(L-ornithine) in low concentrations of sodium dodecyl sulfate

✍ Scribed by Kunio Takeda

• Publisher: Wiley (John Wiley & Sons)
• Year: 1985
• Tongue: English
• Weight: 620 KB
• Volume: 24
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360240408

✦ Synopsis

Conformational changes of poly(i-ornithine) [(Orn),] were studied in a sodium dodecyl sulfate (NaDodSO,) solution by CD. (Orn), adopted a n unstable and a stable helical structure below and above the NaDodSO, concentration range where &structure was favored, respectively. CD stopped-flow was used to monitor the transitions from coil to the unstable helix, from the helix to /3-structure, and from coil to p-structure. Only the rate of the helix to p-structure transition was accelerated by an increase in NaDodSO, concentration, whereas the rates of the others were independent of NaDodSO, concentration. The fractions of coil, a-helix, and p-structure in each conformation of (Om), caused by NaDodSO, were computed by simulating a mixed spectrum of typical CD spectra for these structures to the experimentally obtained spectrum. The contents of the unstable and stable helical structures were less than 50 and 73%, respectively.