细胞定位：Secreted
序列相似性：Belongs to the peptidase S1 family. Elastase subfamily.
弹性蛋白酶来源于猪胰腺，广泛应用于组织与细胞解离操作，可有效分离 II 型肺细胞。弹性蛋白在结缔组织弹性纤维中含量最高，因此弹性蛋白酶常用于解离具有丰富细胞间纤维网络的组织。包裹结缔组织细胞与纤维的粘稠胞外基质是多种糖蛋白的复杂混合物；鉴于该基质的复杂性，将弹性蛋白酶与胶原酶、胰蛋白酶、糜蛋白酶等其他酶联合使用时，蛋白消化效果最佳。
弹性蛋白酶分子量为 25900 道尔顿，最适 pH 为 8.5。弹性蛋白酶属于丝氨酸蛋白酶，由含 240 个氨基酸残基的单条肽链构成，带有 4 个二硫键。
其活性中心由多个亚位点组成，对中性氨基酸邻近的肽键具有特异性。该酶同时具备酯酶与酰胺酶活性。弹性蛋白酶可水解多种蛋白底物，在蛋白酶中独有水解天然弹性蛋白的能力；天然弹性蛋白不会被胰蛋白酶、糜蛋白酶或胃蛋白酶降解。弹性蛋白酶在胰腺中以无活性酶原（弹性蛋白酶原）形式合成，在十二指肠中由胰蛋白酶激活；血液组分与细菌中也存在弹性蛋白酶。
该酶可被二异丙基氟磷酸（DFP）、烷基异氰酸酯抑制；丙氨酸、缬氨酸、亮氨酸、异亮氨酸二肽衍生物是有效的竞争性抑制剂。大豆胰蛋白酶抑制剂与激肽释放酶抑制剂仅抑制其蛋白水解活性，不抑制弹性蛋白水解活性。弹性蛋白酶采用可溶性底物 SucAla3NA 进行检测。N - 琥珀酰 - L - 丙氨酰 - L - 丙氨酰 - L - 丙氨酸对硝基苯胺水解，使 410nm 处吸光度升高。
稳定性：pH 低于 3~4 时弹性蛋白酶不稳定。干粉状态下，2–8℃保存可稳定 6–12 个月。
弹性蛋白酶特性
分子量：26.0 kDa
最适 pH：8.5
等电点：9.5
消光系数：54870 cm⁻¹・M⁻¹（理论值）；E1%,280 = 21.18（理论值）
活性中心残基：组氨酸（H71）、天冬氨酸（D119）、丝氨酸（S214）
抑制剂：
- 可被丙氨酸、缬氨酸、亮氨酸、异亮氨酸的二肽衍生物竞争性抑制
- 天然来源抑制剂（如丝氨酸蛋白酶抑制剂 serpins）
- 修饰型天然抑制剂
- 硫酸化修饰脂质
Cell localization: Secreted
Sequence similarity: Belongs to the peptidase S1 family. Elastase subfamily
Elastase is prepared from porcine pancreas. It is extensively used in tissue and cell dissociation procedures. Elastase is effective in the isolation of Type II lung cells. Because elastin is found in the highest concentrations in the elastic fibers of connective tissues, elastase is frequently used to dissociate tissues which contain extensive intercellular fiber networks. The viscous extracellular ground substance in which connective tissue cells and fibers are embedded is a complex mixture of various glycoproteins. Given the complexity of this matrix, proteolytic digestion proceeds best when elastase is used in concert with other enzymes such as collagenase, trypsin and chymotrypsin.
Elastase has a molecular weight of 25,900 daltons, and the optimum pH is 8.5. Elastase is a serine protease consisting of a single peptide chain of 240 residues with four disulfide bridges.
It is possible that the active center is composed of several subsites with a specificity for peptide bonds adjacent to neutral amino acids. It also exhibits esterase and amidase activity. While elastase will hydrolyze a wide variety of protein substrates, it is unique among proteases in its ability to hydrolyze native elastin, a substrate not attacked by trypsin, chymotrypsin or pepsin. It is produced in the pancreas as an inactive zymogen, proelastase, and activated in the duodenum by trypsin.
Elastase is also found in blood components and bacteria.
The enzyme is inhibited by diisopropylphosphofluoridate (DFP) and alkyl isocyanates; derivatives of dipeptides of alanine, valine, leucine and isoleucine are effective competitive inhibitors. Soybean trypsin inhibitor and kallikrein inhibitor suppress proteolytic but not elastolytic activity. Elastase is assayed with a soluble substrate SucAla3NA. Hydrolysis of N-succinyl-L-Ala-L-Ala-L-Ala-p-nitroanilide causes absorbance increase at 410 nm.
Stability: Elastase is unstable below pH 3-4. When stored as a dry powder the enzyme is stable for 6-12 months at 2 - 8°C.
Characteristics of Elastase
Molecular Weight: 26.0 kDa
Optimal pH: 8.5
Isoelectric point: 9.5
Extinction Coefficient: 54,870 cm⁻¹ M⁻¹ (Theoretical); E1%, 280 = 21.18 (Theoretical)
Active Site Residues: Histidine (H71), Aspartic acid (D119), Serine (S214)
Inhibitors:
- Competitively inhibited by derivatives of dipeptides of alanine, valine, leucine, and isoleucine
- Inhibitors from natural sources (e.g. serpins)
- Modified natural inhibitors
- Sulfate-modified lipids
D23191094
危险品化学品经营许可证（带存储）