Rare Missense Mutations in the Calcium Channel β2 Subunit Gene of Autistic Patients Reduce Time-Dependent Inactivation of CaV1.2

Abstract

change in the pore size due to the intrinsic heterogeneity in the fluorescently labeled MscL pentamers where various stoichiometry of the donors and acceptors are present. Furthermore, we have found that sticking the channel to a surface alters the function of them. To get around these two problems, we performed single-molecule FRET experiments using an Alternating Laser EXcitation (ALEX) apparatus. By using alternating lasers of wavelengths 488 nm and 561 nm to excite directly the donors (Alexa488) and acceptors (Alexa568) present in single diffusing MscL molecules which are incorporated in 50 nm liposomes, both the distance-based FRET efficiency E and stoichiometrybased ratio S could be measured. Our single-molecule experiments show that the addition of an asymmetric lipid (LPC) to the liposomes opens the channels, consistent with the results from ensemble measurements.