Protein camouflage in cytochrome c-calixarene complexes.
Small molecules that recognize protein surfaces are important tools for modifying protein interaction properties. Since the 1980s, several thousand studies concerning calixarenes and host-guest interactions have been published. Although there is growing interest in protein-calixarene interactions, only limited structural information has been available to date. We now report the crystal structure of a protein-calixarene complex. The water-soluble p-sulfonatocalix[4]arene is shown to bind the lysine-rich cytochrome c at three different sites. Binding curves obtained from NMR titrations reveal an interaction process that involves two or more binding sites. Together, the data indicate a dynamic complex in which the calixarene explores the surface of cytochrome c. In addition to providing valuable information on protein recognition, the data also indicate that the calixarene is a mediator of protein-protein interactions, with potential applications in generating assemblies and promoting crystallization.
School of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland.
Róise E
RE
McGovern
Humberto
H
Fernandes
Amir R
AR
Khan
Nicholas P
NP
Power
Peter B
PB
Crowley
D001665:Binding Sites; D047250:Calixarenes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D045304:Cytochromes c / Q000737:chemistry / Q000378:metabolism*; D010636:Phenols / Q000737:chemistry; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D012997:Solvents / Q000737:chemistry; D055672:Static Electricity
D010636:Phenols; D012997:Solvents; C121325:calix(4)arene; D047250:Calixarenes; D045304:Cytochromes c