Zinc deficiency classically causes acrodermatitis enteropathica. Zinc is a cofactor for >300 enzymes. Which enzyme's zinc dependence explains impaired wound healing in zinc deficiency?
- A Matrix metalloproteinases (MMPs) — remodelling extracellular matrix; zinc-dependent catalytic mechanism ✓
- B Lysyl oxidase — cross-linking collagen and elastin
- C Prolyl hydroxylase — hydroxylating proline in collagen
- D Collagen glycosyltransferase — adding sugars to collagen hydroxylysine
Explanation
Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases critical for ECM remodelling during all phases of wound healing (debridement, angiogenesis, granulation tissue remodelling). Their catalytic domain contains a zinc ion at the active site essential for peptide bond hydrolysis. Zinc deficiency impairs MMP activity as well as the function of Zn-finger transcription factors (regulating collagen gene expression), thymidine kinase (affecting cell proliferation), and antioxidant SOD (Cu/Zn-SOD). Lysyl oxidase requires copper (not zinc); prolyl hydroxylase requires iron and vitamin C; collagen glycosyltransferase requires manganese.
Reference: Harper's Illustrated Biochemistry, 32nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.