Table 1. Disulfide bond formation in P2X receptors.

Clone	Inter or intra	Effects	Subtype	Reference
K68C/F291C	Inter-subunit	ATP binding site in P2XRs	rP2X1R	[48], [49]
H120C/H213C	Inter-subunit	Inter-subunit Zn2+ binding site	rP2X2R	[50]
E167C/R290C	Inter-subunit	The distance between these two residues is less than 4.6 Å	rP2X2R	[51]
E59C/Q321C	Inter-subunit	Lateral fenestrations become larger when the channel opens	rP2X2R	[52]
E63C/R274C	Inter-subunit	ATP triggers relative movement of adjacent subunits head to tail	rP2X2R	[38]
V48C/I328C	Inter-subunit	Orientation of P2XR subunits; outward motion of each subunit	rP2X2R	[21]
K190C/N284C G60C/D320C I62C/L318C P196C/D320C P196C/K322C R197C/K322C F188C/N284C	Inter-subunit	ATP triggers relative movement of adjacent subunits	hP2X1R	[53]