It is composed of two identical subunits which are held together by disulfide bonds. The monomer of this protein has structural similarity to several members of the beta-galactoside-binding S-type lectin family, but it could not bind beta-galactoside. This is because the ligand binding site is lack of key residue for binding beta-galactoside. [5]It is a galectin-like protein. The ligand of this protein is still unknown.
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^Bohn H, Kraus W, Winckler W (Jul 1983). "Purification and characterization of two new soluble placental tissue proteins (PP13 and PP17)". Oncodevelopmental Biology and Medicine. 4 (5): 343–50. PMID6856484.
^Than NG, Sumegi B, Than GN, Berente Z, Bohn H (November 1999). "Isolation and sequence analysis of a cDNA encoding human placental tissue protein 13 (PP13), a new lysophospholipase, homologue of human eosinophil Charcot-Leyden Crystal protein". Placenta. 20 (8): 703–10. doi:10.1053/plac.1999.0436. PMID10527825.