Serine

Some important facts about Serine
It was first obtained from silk protein in 1865. It occurs in the active sites of chymotrypsin, trypsin
The nerve gases and many substances used in insecticides have been shown to act by combining with a residue of serine in the active site of acetylcholine esterase, inhibiting the enzyme completely.
Its side chain can undergo O-linked glycosylation. It is phosphorylated by kinases during cell signalling in eukaryotes. Phosphorylated serine residues are often referred to as phosphoserine
It acts as a neuronal signaling molecule. Serine is also a precursor to Folate
The Serine octamer cluster in physical chemistry is an unusually stable cluster consisting of eight serine molecules (Ser) implicated in the origin of homochirality.
Serine is required for the immune system as it assists in the production of immunoglobulins and antibodies. Some derivatives (e.g. ethanolamine) are also important components of the phospholipids found in biological membranes.
It is also used in cosmetics as a skin moisturizer. Serine helps produce immunoglobulins for a strong immune system, and also aids in the absorption of creatine, a substance made from amino acids that helps build and maintain all the muscles in the body, including the heart.

Effect of high intake
Elevated serine levels may cause immune suppression and psychological symptoms as in cerebral allergies

Metabolism
It can be synthesized in the body from other metabolites (Glycine) so it is a non-essential amino acid. In order for serine to be manufactured in the body, sufficient amounts of vitamin B3 and vitamin B6, and folic acid must be present.
It participates in the biosynthesis of purines and pyrimidines, glycine, cysteine and tryptophan (in bacteria).
Serine relates to the interconversion to glucose by the way of gluconeogenesis and to many other substances including sphingosine and the phosphatides, which are part of the myelin covering of the nerves

Deficiency symptoms
Low levels of serine may contribute to chronic fatigue syndrome (CFS) and fibromyalgia (FM).

Source
It is found in meats and dairy products, wheat gluten, peanuts as well as soy products.