In this scenario, unbound proteins are predominantly in the ligand-free (apo) structure.

“Right.” He back-pocketed the notebook and lifted the Nikon from my bag. “Take a few steps down the hill and point toward the ruins so I can get both in one shot.”

Briefly, this story tells of the adventures of a commercial traveler afflicted with stampomania. This amiable and garrulous gentleman falls in with a druggist somewhere in the states and at each recurring trip manages to entangle himself and the weak knight of the pestle in the enchanting and entrancing mysteries of philately […]

That man is a mystery.