Histidine is also referred to as a metalloprotein as it can combine and generate metals (like copper and iron) that support proper functioning of some organs.
Glycerine is an amino acid that also functions as a building block for other proteins that help the body. The liver produces it along with other amino acids such as serine and threonine.
L-lysine is important as the muscles need it for growth and turnover.
Sulfur is a nutrient that is required for optimal health.