Vitamin K and energy transduction: a base strength amplification mechanism.
Energy transfer provides an arrow in the metabolism of living systems. Direct energetic coupling of chemical transformations, such that the free energy generated in one reaction is channeled to another, is the essence of energy transfer, whereas the purpose is the production of high-energy chemical intermediates. Vitamin K provides a particularly instructive example of energy transfer. A key principle at work in the vitamin K system can be termed "base strength amplification." In the base strength amplification sequence, the free energy of oxygenation of vitamin K hydroquinone (vitamin KH2) is used to transform a weak base to a strong base in order to effect proton removal from selected glutamate (Glu) residues in the blood-clotting proteins.
Dowd
P
P
Department of Chemistry, University of Pittsburgh, PA 15260, USA.
Hershline
R
R
Ham
S W
SW
Naganathan
S
S
D015055:1-Carboxyglutamic Acid / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D001779:Blood Coagulation Factors / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D019735:Carbon-Carbon Ligases; D003486:Cyanides / Q000494:pharmacology; D004734:Energy Metabolism; D006863:Hydrogen-Ion Concentration; D008025:Ligases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D013816:Thermodynamics; D014812:Vitamin K / Q000378:metabolism*; D010837:Vitamin K 1 / Q000031:analogs & derivatives / Q000378:metabolism
D001779:Blood Coagulation Factors; D003486:Cyanides; D014812:Vitamin K; C016186:vitamin K1 oxide; D015055:1-Carboxyglutamic Acid; C028843:vitamin K1 hydroquinone; D010837:Vitamin K 1; D008025:Ligases; D019735:Carbon-Carbon Ligases; C020660:glutamyl carboxylase; D010100:Oxygen; D002118:Calcium