[HTML][HTML] Novel insight into the mechanism of the vitamin K oxidoreductase (VKOR): electron relay through Cys43 and Cys51 reduces VKOR to allow vitamin K …

MA Rishavy, A Usubalieva, KW Hallgren… - Journal of Biological …, 2011 - ASBMB
The vitamin K oxidoreductase (VKOR) reduces vitamin K to support the carboxylation and
consequent activation of vitamin K-dependent proteins, but the mechanism of reduction is …

[HTML][HTML] Mutations in the GGCX and ABCC6 genes in a family with pseudoxanthoma elasticum-like phenotypes

…, MY Hurley, MA Rishavy, KW Hallgren… - Journal of investigative …, 2009 - Elsevier
A characteristic feature of classic pseudoxanthoma elasticum (PXE), an autosomal recessive
disorder caused by mutations in the ABCC6 gene, is aberrant mineralization of connective …

[HTML][HTML] The vitamin K oxidoreductase is a multimer that efficiently reduces vitamin K epoxide to hydroquinone to allow vitamin K-dependent protein carboxylation

MA Rishavy, KW Hallgren, LA Wilson… - Journal of Biological …, 2013 - ASBMB
The vitamin K oxidoreductase (VKORC1) recycles vitamin K to support the activation of vitamin
K-dependent (VKD) proteins, which have diverse functions that include hemostasis and …

Carboxylase overexpression effects full carboxylation but poor release and secretion of factor IX: implications for the release of vitamin K-dependent proteins

KW Hallgren, EL Hommema, BA McNally… - Biochemistry, 2002 - ACS Publications
Vitamin K-dependent (VKD) proteins are modified by the VKD carboxylase as they transit
through the endoplasmic reticulum. In a reaction required for their activity, clusters of Glu's are …

r-VKORC1 expression in factor IX BHK cells increases the extent of factor IX carboxylation but is limited by saturation of another carboxylation component or by a shift …

KW Hallgren, W Qian, AV Yakubenko, KW Runge… - Biochemistry, 2006 - ACS Publications
Carboxylation of vitamin K-dependent (VKD) proteins is required for their activity and depends
on reduced vitamin K generated by vitamin K oxidoreductase (VKOR) and a redox protein …

Compound heterozygosity of novel missense mutations in the gamma-glutamyl-carboxylase gene causes hereditary combined vitamin K–dependent coagulation …

D Darghouth, KW Hallgren, RL Shtofman, A Mrad… - Blood, 2006 - ashpublications.org
Hereditary combined vitamin K–dependent (VKD) coagulation factor deficiency is an autosomal
recessive bleeding disorder associated with defects in either the γ-carboxylase, which …

Warfarin alters vitamin K metabolism: a surprising mechanism of VKORC1 uncoupling necessitates an additional reductase

MA Rishavy, KW Hallgren, L Wilson… - Blood, The Journal …, 2018 - ashpublications.org
The anticoagulant warfarin inhibits the vitamin K oxidoreductase (VKORC1), which generates
vitamin K hydroquinone (KH 2 ) required for the carboxylation and consequent activation …

Brønsted analysis reveals Lys218 as the carboxylase active site base that deprotonates vitamin K hydroquinone to initiate vitamin K-dependent protein carboxylation

MA Rishavy, KW Hallgren, AV Yakubenko… - Biochemistry, 2006 - ACS Publications
The vitamin K-dependent (VKD) carboxylase converts Glu's to carboxylated Glu's in VKD
proteins to render them functional in a broad range of physiologies. The carboxylase uses …

Methylation of γ-carboxylated Glu (Gla) allows detection by liquid chromatography–mass spectrometry and the identification of gla residues in the γ-glutamyl …

KW Hallgren, D Zhang, M Kinter, B Willard… - Journal of proteome …, 2013 - ACS Publications
γ-Carboxylated Glu (Gla) is a post-translational modification required for the activity of vitamin
K-dependent (VKD) proteins that has been difficult to study by mass spectrometry due to …

A new model for vitamin K-dependent carboxylation: the catalytic base that deprotonates vitamin K hydroquinone is not Cys but an activated amine

MA Rishavy, BN Pudota, KW Hallgren… - Proceedings of the …, 2004 - National Acad Sciences
Vitamin K-dependent (VKD) proteins require carboxylation for diverse functions that include
hemostasis, apoptosis, and Ca 2+ homeostasis, yet the mechanism of carboxylation is not …