Divalent metal ion mediated interaction of proteins with negatively charged membranes. A model study employing molecular mechanics.
Previous molecular mechanics calculations on the effect of Ca(II) and Mg(II) ions on the conformation of the 18-23 loop of bovine prothrombin [Maynard et al. 1988, Int. J. Peptide Protein Res. 31, 137-149] are extended to include the effect of a model phospholipid head group methyl[L-seryl] phosphate. Whereas the conformation of the Gla-21 Pro-22 amide bond remains decidedly trans in the absence of the model head group, in its presence, the cis Ca(II) ion induced (but not Mg(II] form is significantly lowered in relative energy. The low energy Ca(II) structures establish a coordination sphere with more ligands than do the low energy Mg(II) ion structures.
Cain
J D
JD
Department of Chemistry, United States Air Force Academy, Colorado Springs, CO.
Deerfield
D W
DW
Hiskey
R G
RG
Pedersen
L G
LG
D000818:Animals; D002118:Calcium; D002413:Cations, Divalent; D002417:Cattle; D002462:Cell Membrane; D007536:Isomerism; D008274:Magnesium; D008958:Models, Molecular; D010743:Phospholipids; D011487:Protein Conformation; D011516:Prothrombin; D012984:Software; D013816:Thermodynamics
D002413:Cations, Divalent; D010743:Phospholipids; D011516:Prothrombin; D008274:Magnesium; D002118:Calcium