The contribution of conformational adjustments and long-range electrostatic forces to the CD2/CD58 interaction.
CD2 is a T cell surface molecule that enhances T and natural killer cell function by binding its ligands CD58 (humans) and CD48 (rodents) on antigen-presenting or target cells. Here we show that the CD2/CD58 interaction is enthalpically driven and accompanied by unfavorable entropic changes. Taken together with structural studies, this indicates that binding is accompanied by energetically significant conformational adjustments. Despite having a highly charged binding interface, neither the affinity nor the rate constants of the CD2/CD58 interaction were affected by changes in ionic strength, indicating that long-range electrostatic forces make no net contribution to binding.
Kearney
Alice
A
Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom.
Avramovic
Adam
A
Castro
Mónica A A
MA
Carmo
Alexandre M
AM
Davis
Simon J
SJ
van der Merwe
P Anton
PA
D000818:Animals; D015703:Antigens, CD / Q000737:chemistry / Q000378:metabolism; D018801:CD2 Antigens / Q000737:chemistry* / Q000378:metabolism; D000071178:CD48 Antigen; D018968:CD58 Antigens / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000737:chemistry / Q000378:metabolism; D009994:Osmolar Concentration; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D012377:Rodentia; D055672:Static Electricity; D020349:Surface Plasmon Resonance; D013601:T-Lymphocytes / Q000737:chemistry / Q000378:metabolism
D015703:Antigens, CD; D018801:CD2 Antigens; D000071178:CD48 Antigen; C000604065:CD48 protein, human; D018968:CD58 Antigens