Metalloproteins are metal-dependent proteins, i.e. they require certain metal ions (copper, magnesium, zinc, etc.) for their correct function in the body. Since proteins are manufactured inside cells by the ribosomes and metal ions are exogenous materials, i.e. are obtained from food, how would a metalloprotein and its respective metal ion find each other in the body? Are the metal ions taken inside all body cells? Does the meeting take place in the blood?
A quick Google search retrieved nothing useful.