Application
Can be used in conjunction with E64-d and Leupeptin A to inhibit the degradation of autophagic cargo inside autophagosomes. For this application, the working concentration is typically between 1-10 μM.
Other Notes
Strong inhibitor of acid proteases - pepsin, cathepsin D, renin1,2,3
Preparation Note
Pepstatin can be dissolved at 1 mg/ml in 10% (v/v) acetic acid in methanol (9:1 methanol:acetic acid). The inclusion of acetic acid may be necessary to dissolve this peptide in methanol or DMSO. It has been dissolved at 1 to 2 mg/ml in ethanol, but heat may be required for complete dissolution. Solutions of Pepstatin A can be heated as high as 60 °C without any decomposition of the peptide. Stock solutions at 1 mg/ml are stable at least a week at 4 °C. A 1 mM solution in methanol or DMSO is stable for months at -20 °C. If solutions become darker yellow, the reagent is hydrolyzing.A working concentration of 1 μM is stable for at least one day at room temperature.
Unit Definition
1 U corresponds to the amount of inhibitor which reduces the activity of pepsin by 1 U (1 U corresponds to the amount of enzyme which increases the absorbance at 280 nm by 0.001 per minute at pH 2.0 and 37°C (Hemoglobin, Fluka-No. 51290, as substrate, in an endvolume of 16 ml)); 10′000 absorbance-U as described above are equivalent to ～1 Bergmeyer-U (when 1 pepsin-U is the amount of enzyme which hydrolyzes 1 μmol acetyl-L-phenylalanyl-3,5-diiodo-L-tyrosin per minute at pH 2.0 and 37°C)
Biochem/physiol Actions
Pepstatin A is an inhibitor of acid proteases (aspartyl peptidases). It forms a 1:1 complex with proteases such as pepsin, renin, cathepsin D, bovine chymosin, and protease B (Aspergillus niger). The inhibitor is highly selective and does not inhibit thiol proteases, neutral proteases, or serine proteases. Solubilized γ-secretase and retroviral protease are also inhibited by Pepstatin A. It has been used to characterize proteases from several sources. |
Application
Can be used in conjunction with E64-d and Leupeptin A to inhibit the degradation of autophagic cargo inside autophagosomes. For this application, the working concentration is typically between 1-10 μM.
Other Notes
Strong inhibitor of acid proteases - pepsin, cathepsin D, renin1,2,3
Preparation Note
胃酶抑素可以 1mg/ml 的浓度溶于含 10% (v/v) 乙酸的甲醇（9:1 甲醇:乙酸）中。乙酸的添加对于该多肽在甲醇或 DMSO 中的溶解可能是必需的。它能以 1 至 2mg/ml 的浓度溶于乙醇，但完全溶解需要加热。胃酶抑素 A 的溶液可加热至高达 60°C，而不会发生任何降解。 1mg/ml 的储存液在 4°C 下可稳定至少一周。1mM 的甲醇或 DMSO 溶液在 -20°C 下可稳定数月。如果溶液逐渐变为深黄色，说明试剂正在发生水解。 工作浓度为 1μM 时，可在室温下稳定至少一天。
Unit Definition
1 U corresponds to the amount of inhibitor which reduces the activity of pepsin by 1 U (1 U corresponds to the amount of enzyme which increases the absorbance at 280 nm by 0.001 per minute at pH 2.0 and 37°C (Hemoglobin, Fluka-No. 51290, as substrate, in an endvolume of 16 ml)); 10′000 absorbance-U as described above are equivalent to ～1 Bergmeyer-U (when 1 pepsin-U is the amount of enzyme which hydrolyzes 1 μmol acetyl-L-phenylalanyl-3,5-diiodo-L-tyrosin per minute at pH 2.0 and 37°C)
Biochem/physiol Actions
胃酶抑素 A 是酸性蛋白酶（天冬氨酰基肽酶）的抑制剂。它可与蛋白酶如胃蛋白酶、肾素、组织蛋白酶 D、牛凝乳酶和蛋白酶 B（黑曲霉）形成 1:1 的复合物。该抑制剂具有高度的选择性，不会抑制硫醇蛋白酶、中性蛋白酶或丝氨酸蛋白酶。可溶性 γ-分泌酶和逆转录病毒蛋白酶也可被胃酶抑素 A 抑制。它已用于鉴定多种来源的蛋白酶。 |