Myelin basic protein has multiple calmodulin-binding sites.
Myelin basic protein (MBP) has been shown to bind calmodulin (CaM) in a specific Ca(2+)-dependent manner via a primary target sequence at its C-terminus [Protein Sci. 12 (2003) 1507]. Upon deimination of MBP, the nature of the interaction changed significantly, suggesting either a new binding site or different conformers with different affinities for CaM. In order to resolve this issue, we investigated here the CaM-binding properties of N- and C-terminal deletion mutants of MBP using Trp fluorescence spectroscopy and mass spectrometry. We conclude that there is an additional CaM-binding site on MBP in a central segment (we posit murine residues 82-93) that forms an amphipathic alpha-helix.
Libich
David S
DS
Department of Molecular Biology and Genetics, Biophysics Interdepartmental Group, University of Guelph, 50 Stone Road East, Guelph, Ont., Canada N1G 2W1.
Hill
Christopher M D
CM
Haines
Jeffery D
JD
Harauz
George
G
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002147:Calmodulin / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D004676:Myelin Basic Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D013050:Spectrometry, Fluorescence; D021241:Spectrometry, Mass, Electrospray Ionization; D014364:Tryptophan / Q000737:chemistry
D002147:Calmodulin; D004676:Myelin Basic Protein; D011994:Recombinant Proteins; D014364:Tryptophan