| Method |
"Channel activity of Vpu is proved by reconstitution of the whole protein into planar lipid bilayers
[ref 76]. For this study, Vpu is transcribed in
E. coli
and
purified. Reconstitution has been done either from a detergent solution or from a suspension of Vpu-containing vesicles. It could be shown that Vpu channel
activity is more in preference of monovalent cations
than anions. Currents of up to 2 pA (-80 mV) in a
0.5/0.05 M NaCl solution have been recorded. Reconstitution into a lipid membrane of a synthetic
analogous to the TM [transmembrane] region of Vpu shows channel
activity of up to 60 pS with a preference to monovalent cations [ref 29]. A peptide of the same length with
a scrambled sequence does not exhibit any channel
activity." |