Reactome | VD3 binds GC

VD3 binds GC

Stable Identifier

R-HSA-209738

Type

Reaction [transition]

Species

Homo sapiens

Compartment

plasma membrane, cytosol, extracellular region

ReviewStatus

5/5

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Vitamin D metabolites such as VD3 are lipophilic and must be transported in the circulation bound to plasma proteins. Vitamin D3 is transported to the liver bound to a plasma protein called vitamin D binding protein (GC aka DBP) (Verboven et al. 2002). GC is a 58 kDa circulating glycoprotein that transports vitamin D metabolites. The vast majority of vitamin D metabolites circulate bound to GC (85–90%), some bound to albumin (10–15%), with the remainder (<1%) circulating in the free form. GC has more than 1000-fold stronger binding affinity for vitamin D metabolites than albumin. Thus, the albumin-bound and free fractions of vitamin D metabolites are considered bioavailable (Denburg et al. 2016).

Literature References

PubMed ID	Title	Journal	Year
11799400	A structural basis for the unique binding features of the human vitamin D-binding protein Verboven, C, Rabijns, A, De Maeyer, M, Van Baelen, H, Bouillon, R, De Ranter, C	Nat Struct Biol	2002
27250744	Comparison of Two ELISA Methods and Mass Spectrometry for Measurement of Vitamin D-Binding Protein: Implications for the Assessment of Bioavailable Vitamin D Concentrations Across Genotypes Denburg, MR, Hoofnagle, AN, Sayed, S, Gupta, J, de Boer, IH, Appel, LJ, Durazo-Arvizu, R, Whitehead, K, Feldman, HI, Leonard, MB	J. Bone Miner. Res.	2016