The Chlamydia trachomatis PmpD adhesin forms higher order structures through disulphide-mediated covalent interactions
Fig 3
Inter- and intramolecular disulphide bonding critically influence the biophysical properties of rPmpD.
(A) Oligomeric (Lanes 1–3) and monomeric (Lanes 4–6) rPmpD samples were incubated with loading buffer in the absence or presence of 0.5 M β-mercaptoethanol (β-ME). Native gels were also run with (B) oligomeric or (C) monomeric rPmpD samples incubated in the absence of SDS with differing concentrations of three reducing agents– 10 mM or 5 mM DTT (Lanes 1–2), 25 mM or 2.5 mM TCEP (Lanes 3–4) and 0.5M or 50 mM β-ME (Lanes 5–6). Non-reduced sample was run as a control (Lane 8). (D) oligomeric or (E) monomeric rPmpD were incubated in the presence of trypsin for 30 min, 5 mins, or 2 mins (Lanes 2–4, respectively). Undigested control samples were run in Lane 1 of each gel.