氨肽酶
氨肽酶 性质
| 熔点 | 216-218 °C |
|---|---|
| 储存条件 | 2-8°C |
| 溶解度 | 在水中的溶解度25 mg/mL，澄清，无色 |
| 形态 | 白色至类白色粉末。 |
| 颜色 | 白色 |
| 水溶解性 | Soluble in water (4 mg/ml, warm), DMSO (>25 mg/ml), methanol, acetic acid, dimethyl formamide, and 100% ethanol. |
| BRN | 4628066 |
| 稳定性 | 从购买之日起 2 年内保持稳定。 DMSO、蒸馏水或乙醇中的溶液可在 -20℃ 下储存长达 1 个月。 |
| InChIKey | XGDFITZJGKUSDK-UDYGKFQRSA-N |
| CAS 数据库 | 65391-42-6(CAS DataBase Reference) |
氨肽酶 用途与合成方法
根据最易反应的底物不同可分为亮氨酸氨肽酶、缬氨酸氨肽酶、苯丙氨酸氨肽酶、脯氨酸氨肽酶等。
有关氨肽酶的概述、分类、制备方法、药理作用等是由Chemicalbook的丁红编辑整理。（2015-12-02） 枯草芽孢杆菌 Zj016 发酵液 4 ℃；10 000 r/min 离心10 min； 取上清液；用质量分数为 18 %的(NH4)2SO4澄清；离心取上清液用相对分子质量 50000 的超滤膜超滤浓缩；得浓缩液用相对分子质量 30 000 的超滤膜脱盐；体积分数68 %乙醇醇沉；沉淀真空冷冻干燥得氨肽酶酶活为4.0 ×105U/ g 。 最显著的作用在于脱除蛋白水解液的苦味，如大豆蛋白水解液，多肽的苦味与其N端疏水性氨基酸的量成正比，外肽酶可以有效的切除这些疏水性氨基酸。
用于脱除蛋白水解液的苦味
氨肽酶最显著的作用在于脱除蛋白水解液的苦味，如大豆蛋白水解液，多肽的苦味与其N端疏水性氨基酸的量成正比，外肽酶可以有效的切除这些疏水性氨基酸。
蛋白质的深度水解
与蛋白酶复合使用，可以大幅度提高蛋白质的水解度。在酱油酿造、干酪生产及其它蛋白水解产品的制备过程中，可以提高蛋白质的利用率，节省成本。如崔春、赵谋明等利用风味蛋白酶（蛋白酶和氨肽酶的复合体）深度酶解蓝园鱼参蛋白，酶解 6h 后蛋白质的利用率即达到 83.3%，21h 时水解度达到59.7%。
生物活性多肽的制备
生物活性多肽大部分是细胞生长因子，它们在体内含量极低，但生物活性极高，对多种细胞生理功能和代谢活动发挥着生物调节作用。具有保健和美容的功能。通过控制蛋白质的酶解来得到特定的活性肽是制备活性多肽的一种安全且高效的途径。刘通讯等先用蛋白酶对大豆分离蛋白进行水解，然后再用氨肽酶进行水解，研究发现，产品中的多肽含量相对单一用蛋白酶水解约能提高 12%左右。
可用作蛋白质序列测定的分子工具，在食品工业上通常与蛋白酶复合使用，广泛应用于调味品和奶酪的生产、蛋白水解液脱苦 、蛋白质深度水解和多肽的制备等方面。 Bestatin hydrochloride (Ubenimex hydrochloride) 是 CD13 (Aminopeptidase N)/APN 和 leukotriene A4 hydrolase 抑制剂，常用于癌症研究。Bestatin enhances ATRA-induced differentiation and inhibits ATRA-driven phosphorylation of p38 MAPK in ATRA-sensitive APL NB4 cells. Bestatin can not reverse the differentiation block in ATRA-resistant APL MR2 cells. CD13 ligation with anti-CD13 antibody WM-15 results in phosphorylation of p38 MAPK, reduces the inhibition of Bestatin on the phosphorylation of p38 MAPK, and completely abolishes the enhancement of Bestatin on ATRA-inducing differentiation in NB4 cells. Bestatin (600 μM)-treated cells progress slower through the cell cycle due to decreased rate of cell growth and the frequency of cell division. Bestatin inhibits the frequency of mitosis and the inherent multinuclearity in D. discoideum, and is not cytotoxic to D. discoideum cells at 0-600 μM. Bestatin inhibits aminopeptidase activity in lysates of PsaA-GFP- and GFP-expressing cells by 69.39% ± 10.5% and 39.93% ± 18.7% of control, respectively.
Bestatin (20 μM) significantly reduces CD13 expression in diabetic mice and results a significant inhibition of MMP-9 specific gelationolytic band densities compared to diabetic vehicle-treated mice. Bestatin treatment significantly inhibits the expression of VEGF and heparanase in diabetic mice. Intravitreal bestatin treatment significantly downregulates the expression of both HIF-1α and VEGF in diabetic mice retinas. Furthermore, the upregulated expression of heparanase in diabetic mice retinas is significantly inhibited by intravitreal bestatin treatment. Bestatin (10, 1, and 0.1mg/kg, i.p.) treatment before the antigen-potentiated humoral response to SRBC results in an increased number of splenocytes producing hemolytic anti-SRBC antibodies (PFC) and the 2-ME-resistant serum hemagglutinin titer (at a dose of 0.1 mg/kg). Bestatin (1 and 0.1 mg/kg) administered to mice five times on alternate days after cyclophosphamide injection does not change the suppressive effect of the drug regarding the number of PFC, and even causes the further decrease of the total anti-SRBC hemagglutinins at dose of 1 mg/kg on day 7 after antigen stimulation.
