These five are alanine, aspartic acid, asparagine, glutamic acid and serine. Aspartate can be converted into lysine, asparagine, methionine and threonine. The oxaloacetate/aspartate family of amino acids is composed of lysine, asparagine, methionine, threonine, and isoleucine. Otherwise histidine, glutamate, asparagine, cysteine are susceptible to methylation. Proteins consist of the amino acids glutamine, arginine and asparagine. Asparagine is hydrolyzed to aspartate by asparaginase. The glycine substitution prevents deamidation of the acid-sensitive asparagine at acidic pH. The biosynthesis of asparagine originates with aspartate using a transaminase enzyme. A pair of arginine and asparagine residues on C2 stabilizes the transition state. Further transaminations are carried out make other amino acids (most commonly asparagine) from glutamine. These reactions are facilitated by transaminases in order to produce aspartate and asparagine from oxaloacetate. A seventh catalytic type of proteolytic enzymes, asparagine peptide lyase, was described in 2011. It has two potential N-linked glycosylation sites at asparagine (Asn) 16 and Asn27. Both heavy chains are glycosylated at the asparagine in position 296. It contains isovaleric acid, salicylic acid, asparagine, sterols, and flavonoids.