Vitamin K-dependent protein
A Vitamin K-dependent protein is a protein that can bind calcium ions but only after being carboxylated. This carboxylation, said to activate the protein, is facilitated by some form of Vitamin K1 or Vitamin K2. The relevant part of a vitamin K-dependent protein is a Gla domain, and such a protein is informally called a Gla protein. Some Gla proteins have "Gla" in their name, for example Matrix Gla protein, but many don't, such as osteocalcin.
