Table 1 Mass of the PC and MV portals determined from CDMS spectra.
SampleTheoretical mass of
12-mer (kDa)		Measured mass of
12-mer (kDa)*
PC portal1005.61027 ± 0.009
MV portal992.9997.2 ± 0.004

*The measured masses were obtained by fitting a Gaussian to the measured peak and taking the center of the Gaussian. The mass difference observed between the PC and MV portals is due to the His tag bound to the PM. The uncertainties for the measured masses are ±1 SD for multiple measurements on different samples.