Lactoferrin binding of recombinant proteins. (A) SDS-PAGE of purified recombinant proteins. (B) Binding of recombinant proteins to human lactoferrin. (C) Binding of recombinant proteins to human transferrin. Lane 1, molecular weight markers; lane 2, Q8 rLbpA; lane 3, Q8 rLbpB; lane 4, 4223 rLbpB; lane 5, 4223 rTbpB.