You'll get more hits if you drop the space in metalloprotein.
http://www.google.com/search?hl=en&safe=off&q=metalloprotein
Actually, David's place of employment is one of the premier research institutions in the world for this subject.
Simply put, a metalloprotein is any protein that has a metal in it. An example is hemoglobin- the protein that carries oxygen in your...I mean our blood (yeah "our" that's right, I'm one of you, my skin always has this pallor). Hemoglobin is a protein, but the business end that carries the oxygen is an atom of iron. The protein part is mostly scaffolding.
PS: And for 'energy supplements' or 'diet and exercise enhancements'. That sh*t is about as effective as the products that claim to give you a couple extra inches...in length and girth.
Eat well, excercise. That's the ticket.
(David- don't be giving me away now...)