TABLE 1.

Single-channel properties of recombinant chlamydial MOMPs^a

MOMP	Reversal potential (mV) in 250 mM vs. 50 mM KCl	Conductance (pS) in symmetric KCl
		50 mM	500 mM
C. psittaci	−20.0 ± 1.5 (8)	204 ± 19 (8)	882 ± 88 (5)
C. trachomatis	−14.4 ± 0.82 (8)**	172 ± 19 (8)NS	575 ± 61 (6)*
C. psittaci (A303V/F343V)	−21.7 + 2.4 (6)	199 ± 14 (7)	808 ± 76 (6)
C. trachomatis (A277V/T318V)	−14.5 + 1.9 (5)**	174 ± 17 (7)NS	568 ± 80 (6)**
C. psittaci−VS4	−27.7 ± 4.0 (4)	184 ± 23 (5)
C. trachomatis−VS4	−30.0 ± 2.8 (4)NS	193 ± 14 (4)NS
C. psittaci−VS4 plus C. trachomatis VS4	−22.1 ± 2.4 (6)	195 ± 14 (5)	623 ± 107 (5)
C. trachomatis−VS4 plus C. psittaci VS4	−20.7 ± 2.9 (5)NS	185 ± 27 (5)NS	432 ± 47 (6)*

^aSelectivity and conductance measurements (means ± SD for n independent experiments [n in parentheses]) for full-length wild-type MOMP channels, channels containing point mutations, deletion constructs (−VS4), and hybrid channels (VS4 domains exchanged as indicated) were carried out. The results of vertical pairwise statistical comparisons are shown (NS, not significant; *, P < 0.01; **, P < 0.001). The differences between the mean reversal potentials for C. trachomatis MOMP containing the C. psittaci VS4 domain and full-length C. trachomatis MOMP, or C. trachomatis MOMP containing point mutations, are also significant (P < 0.001 and P < 0.01, respectively). In addition, the mean reversal potentials for C. psittaci MOMP−VS4 and C. trachomatis MOMP−VS4 differ significantly from those of the corresponding full-length proteins (P < 0.01 and P < 0.001, respectively) and from the corresponding full-length proteins with point mutations (P < 0.02 and P < 0.001, respectively).