Biophysical characterization of Vpu from HIV-1 suggests a channel-pore dualism |
| |
Authors: | Mehnert T Routh A Judge P J Lam Y H Fischer D Watts A Fischer W B |
| |
Institution: | Biomembrane Structure Unit, Department of Biochemistry, Oxford University, Oxford OX1 3QU, United Kingdom. |
| |
Abstract: | Vpu from HIV-1 is an 81 amino acid type I integral membrane protein which consists of a cytoplasmic and a transmembrane (TM) domain. The TM domain is known to alter membrane permeability for ions and substrates when inserted into artificial membranes. Peptides corresponding to the TM domain of Vpu (Vpu(1-32)) and mutant peptides (Vpu(1-32)-W23L, Vpu(1-32)-R31V, Vpu(1-32)-S24L) have been synthesized and reconstituted into artificial lipid bilayers. All peptides show channel activity with a main conductance level of around 20 pS. Vpu(1-32)-W23L has a considerable flickering pattern in the recordings and longer open times than Vpu(1-32). Whilst recordings for Vpu(1-32)-R31V are almost indistinguishable from those of the WT peptide, recordings for Vpu(1-32)-S24L do not exhibit any noticeable channel activity. Recordings of WT peptide and Vpu(1-32)-W23L indicate Michaelis-Menten behavior when the salt concentration is increased. Both peptide channels follow the Eisenman series I, indicative for a weak ion channel with almost pore like characteristics. |
| |
Keywords: | Vpu HIV‐1 membrane proteins artificial bilayers ion channels gating |
本文献已被 PubMed 等数据库收录! |
|