Calcium-induced changes in annexin V behaviour in solution as seen by proton NMR spectroscopy.
The behaviour of human annexin V in the presence of calcium was studied by NMR. We observe the formation of well defined dimers, as well as a change in the local dynamics of one His side chain. We assign the observed changes to either His98 or His267 residues and conclude that they could be related either to the hinge-bending motion reported from crystal structures, or to a local side chain rearrangement within the calcium-binding loops concerned. Dimerization was also confirmed by a small-angle neutron-scattering experiment. Under the experimental conditions used, we do not observe the conformational change involving Trp187 seen in previous studies, which occurs at higher relative calcium concentrations.
Département de Biologie Cellulaire et Moléculaire, URA CNRS 1290, CEA Saclay, Gif sur Yvette, France.
J M
JM
Neumann
A
A
Sanson
A
A
Lewit-Bentley
D000595:Amino Acid Sequence; D017304:Annexin A5 / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites / Q000235:genetics; D002118:Calcium / Q000494:pharmacology; D006639:Histidine / Q000737:chemistry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008566:Membranes / Q000737:chemistry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009502:Neutrons; D011487:Protein Conformation / Q000187:drug effects; D011522:Protons; D012542:Scattering, Radiation; D012996:Solutions; D014364:Tryptophan / Q000737:chemistry
D017304:Annexin A5; D011522:Protons; D012996:Solutions; D006639:Histidine; D014364:Tryptophan; D002118:Calcium