About: http://webisa.webdatacommons.org/123447073

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Smith et al., J Mol Biol 224:899-904 (1992); de Vos et al., Science 255:306-312 (1992).Polypeptides can contain amino acids other than the 20 amino acids commonly referred to as the 20 naturally occurring amino acids.
http://www.w3.org/ns/prov#wasQuotedFrom	freepatentsonline.com