Preferential cleavage:hydrophobic, preferablyaromatic, residues in P1 and P1' positions. Cleaves Phe1-Val, Gln4-His, Glu13-Ala, Ala14-Leu, Leu15-Tyr, Tyr16-Leu, Gly23-Phe, Phe24-Phe and Phe25-Tyr bonds in the B chain ofinsulin
^Foltmann B (1981). "Gastric proteinases--structure, function, evolution and mechanism of action".Essays in Biochemistry.17:52–84.PMID6795036.
^James MN, Sielecki AR (1986). "Molecular structure of an aspartic proteinase zymogen, porcine pepsinogen, at 1.8 A resolution".Nature.319 (6048):33–8.doi:10.1038/319033a0.PMID3941737.
^Fruton, J.S.; Brocklehurst, K. (1987). "Aspartyl proteinases". In Neuberger, A. (ed.).New Comprehensive Biochemistry: Hydrolytic Enzymes. Vol. 16. Amsterdam: Elsevier. pp. 1–38.
^Tang J, Wong RN (January 1987). "Evolution in the structure and function of aspartic proteases".Journal of Cellular Biochemistry.33 (1):53–63.doi:10.1002/jcb.240330106.PMID3546346.
^Pohl J, Dunn BM (June 1988). "Secondary enzyme-substrate interactions: kinetic evidence for ionic interactions between substrate side chains and the pepsin active site".Biochemistry.27 (13):4827–34.doi:10.1021/bi00413a037.PMID3139029.
