N-Acetyl-L-alanine is a substrate for Guanine nucleotide-binding protein G(I)/G(S)/G(O) gamma-2 subunit Myelin basic protein GTP-binding nuclear protein Ran Tropomyosin alpha 4 chain HIV-1 Rev binding protein 2 Xaa-Pro dipeptidase Thymosin beta-10 Actin-like protein 3 Alanine aminotransferase Serine/threonine protein phosphatase PP1-beta catalytic subunit 10 kDa heat shock protein (mitochondrial) Calmodulin and Beta-1-syntrophin.

Homocystine is the double-bonded form of homocysteine but it occurs only transiently before being converted to the harmless cystathionine via a vitamin B6-dependent enzyme. Increasing evidence supports a role for an elevation of homocysteine in schizophrenia.

Homoserine is a more reactive variant of the amino acid serine. In this variant the hydroxyl side chain contains an additional CH2 group which brings the hydroxyl group closer to its own carboxyl group allowing it to chemically react to form a five-membered ring.