General description

Extinction Coefficient: E^1% = 21.0 (280 nm)
pI: 9.0

包装

1000 units in glass bottle

Preparation Note

2 次结晶

Unit Definition

在 pH 7.0 和 37°C 下，当在最终体积为 10mL（1cm 光程）的溶液中测定酪蛋白的 TCA 可溶性产物时，一单位每分钟产生的 ΔA₂₈₀ 为 1.0。

Physical form

2.0M NaCl 和 0.03M 半胱氨酸中的悬浮液 (pH 5.0)

Biochem/physiol Actions

Ficin is classified as a thiol protease. It contains a single reactive cysteine at its active site. The amino acid homology of the active site is similar to that of papain. Ficin will cleave proteins at the carboxyl side of Gly, Ser, Thr, Met, Lys, Arg, Tyr, Ala, Asn, and Val. The reported K_m for the chromogenic substrate pGlu-Phe-Leu-p-nitroanilide is 0.43 mM. Ficin is inhibited by iodoacetamide, iodoacetic acid, N-ethylmaleimide, mercuric chloride, DFP (diisopropyl fluorophosphate), TLCK (Na-p-Tosyl-lysine chloromethyl ketone), and TPCK (N-Tosyl-L-phenylalanine chloromethyl ketone). Ficin can be used to generate high yielding F (ab′)₂ fragments from mouse IgG1.