A grafting approach to obtain site-specific metal-binding properties of EF-hand proteins.
The EF-hand calcium-binding loop III from calmodulin was inserted with glycine linkers into the scaffold protein CD2.D1 at three locations to study site-specific calcium binding properties of EF-hand motifs. After insertion, the host protein retains its native structure and forms a 1:1 metal-protein complex for calcium and its analog, lanthanum. Tyrosine-sensitized Tb3+ energy transfer exhibits metal binding and La3+ and Ca2+ compete for the metal binding site. The grafted EF-loop III in different environments has similar La3+ binding affinities, suggesting that it is largely solvated and functions independently from the host protein.
Ye
Yiming
Y
Department of Chemistry, Center of Drug Design, Georgia State University, Atlanta, GA 30303, USA.
Shealy
Sarah
S
Lee
Hsiau-Wei
HW
Torshin
Ivan
I
Harrison
Robert
R
Yang
Jenny J
JJ
D000818:Animals; D001665:Binding Sites; D018801:CD2 Antigens / Q000737:chemistry* / Q000235:genetics; D002118:Calcium / Q000737:chemistry*; D002147:Calmodulin / Q000737:chemistry*; D002942:Circular Dichroism; D020832:EF Hand Motifs; D013058:Mass Spectrometry; D019906:Nuclear Magnetic Resonance, Biomolecular; D011485:Protein Binding; D015202:Protein Engineering; D017510:Protein Folding; D051381:Rats; D013725:Terbium / Q000737:chemistry
D018801:CD2 Antigens; D002147:Calmodulin; D013725:Terbium; D002118:Calcium