Impact of salt bridges on the equilibrium binding and adhesion of human CD2 and CD58.
This study describes quantitative investigations of the impact of single charge mutations on equilibrium binding, kinetics, and the adhesion strength of the CD2-CD58 interaction. Previously steered molecular dynamics simulations guided the selection of the charge mutants investigated, which include the CD2 mutants D31A, K41A, K51A, and K91A. This set includes mutations in which the previous cell aggregation and binding data either agreed or disagreed with the steered molecular dynamics predictions. Surface plasmon resonance measurements quantified the solution binding properties. Adhesion was quantified with the surface force apparatus, which was used previously to study the closely related CD2-CD48 interaction. The results reveal roles that these salt bridges play in equilibrium binding and adhesion. We discuss both the molecular basis of this behavior and its implications for cell adhesion.
Bayas
Marco V
MV
Department of Chemistry and Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Kearney
Alice
A
Avramovic
Adam
A
van der Merwe
P Anton
PA
Leckband
Deborah E
DE
D019943:Amino Acid Substitution; D018801:CD2 Antigens / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018968:CD58 Antigens / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding / Q000235:genetics; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012492:Salts / Q000737:chemistry / Q000378:metabolism
D018801:CD2 Antigens; D018968:CD58 Antigens; D012492:Salts