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. 2012 Sep 25;287(47):39710–39720. doi: 10.1074/jbc.M112.405076

TABLE 3.

Substrate specificity of pseudoalterin on various substrates

Substrate Activity (units/mg)a
Pseudoalterin Myroilysinb Pseudolysinb
Casein 0 8541 7061
Elastinorcein 527.9 243.3 91.1
Gelatin 12.0 4.5 5.0
Bovine-insoluble type I collagen fiber 4.9 3.8 0
Gamma globulinc 0
Furylacryloyl-Gly-Leu-NH2d 0 0 642
Furylacryloyl-Gly-Phe-NH2d 0 0 3,364
Fibrinc No hydrolysis Hydrolyzes α, β, and γ Hydrolyzes α, β, and γ
Oxidized insulin B chain Gly-8↓Ser-9, Glu-13↓Ala-14, Leu-15↓Tyr-16, Tyr-16↓Leu-17, Leu-17↓Val-18, Cys-19↓Gly-20, Glu-21↓Arg-22, Gly-23↓Phe-24, Phe-24↓Phe-25, Lys-29↓Ala-30 Asp-3↓Gln-4, His-5↓Leu-6, Leu-6↓Cys-7, Ser-9↓His-10, His-10↓Leu-11, Tyr-16↓Leu-17, Phe-25↓Tyr-26, Tyr-26↓Thr-27, Thr-27↓Pro-28, Lys-29↓Ala-30 His-5↓Leu-6, His-10↓Leu-11, Ala-14↓Leu-15, Tyr-16↓Leu-17, Leu-17↓Val-18, Gly-23↓Phe-24, Phe-24↓Phe-25, Phe-25↓Tyr-26, Lys-29↓Ala-30

a Unless otherwise indicated, the values are specific activities (in units/mg) at 25 °C. The data are the means of three experiments, and the standard deviations were ≤5%.

b The data on the substrate specificity of myroilysin and pseudolysin are cited from a previous study (13) and the MEROPS Database.

c Hydrolysis of gamma globulin and fibrin by pseudoalterin was performed at 25 °C, and the results were analyzed by SDS-PAGE (supplemental Fig. S6). – indicates not done.

d The proteolytic activities with furylacryloyl-Gly-Leu-NH2 and furylacryloyl-Gly-Phe-NH2 were measured with Feder's method at 25 °C (42); the data are the values of kcat/Km (in m−1 s−1).