pepsin

Pepsin is an endopeptidase that breaks down proteins into smaller peptides and amino acids that can be easily absorbed in the small intestine[1]. Pepsin is stable at pH ranges as high as pH 6. Above this pH, pepsin is rapidly irreversibly inactivated and elevation of pH of the reaction mixture to pH 8 results in complete inactivation of pepsin[2]. Pepsin has been posited to be a reliable biological marker of EER. An immunologic pepsin assay of combined sputum and saliva was determined to be 100% sensitive and 89% specific for detection of EER (based on pH-metry), and an enzymatic test of nasal lavage fluid (100% sensitivity and 92.5% specificity) demonstrated an increased incidence of EER in patients with chronic rhinosinusitis[3]. Cultured hypopharyngeal epithelial (FaDu) cells were exposed to human pepsin (0.1 mg mL) at pH 7.4 for either 1 hour or 12 hours at 37°C and both mitochondria and Golgi complexes were clearly damaged. This finding reveals a novel mechanism by which pepsin could cause cell damage, potentially even in nonacidic refluxate[4].

Sucralfate (Sucrose octasulfate–aluminum complex) 是一种口服活性胃保护剂。它抑制消化性活性，并与黏膜损伤时暴露的带负电荷的上皮下蛋白结合，形成一层粘性层，保护血管床和增殖区。它可用于预防和治疗胃肠道疾病。

Pepsin A 是人和猪胃中的主要蛋白酶，是一种类似胃蛋白酶的胃小蛋白水解酶。Pepsin A 有助于脊椎动物胃中食物蛋白质的蛋白质水解。

Pepstatin (Pepsin Inhibitor S 735A) 是一种天冬氨酸蛋白酶抑制剂，也可抑制 HIV 蛋白酶的活性，具有特异性和口服活性。Pepstatin 可以抑制自噬。

Streptomyces pepsin inhibitor is used as a pepsin inhibitor.

Pepsinostreptin is a pepsin inhibitor that forms a 1:1 complex with pepsin and suppresses its activity.

Aspergillopepsin I (Aspergillus acid protease) 是一种属于天冬氨酸内肽酶类，能广泛特异性催化水解蛋白质中的肽键。

Pepstatin Ammonium is a specific inhibitor of aspartic proteaseproduced by actinomycetes(hemoglobin-pepsin, hemoglobin-proctase, casein-pepsin, casein-proctase, casein-acid protease and hemoglobin-acid protease with IC50s of 4.5 nM, 6.2 nM, 150 nM, 290 nM

Cimetidine (SKF-92334) 是一种可口服的可逆组胺H2受体拮抗剂，Ki 为 0.6 μM。它抑制胃酸分泌，以及胃蛋白酶和胃泌素的输出，具有抗癌和抗炎活性。

Pepstatin (Pepstatin A) Trifluoroacetate 是一种由放线菌产生的特异性天冬氨酸蛋白酶(aspartic proteases)抑制剂，口服活性强。该化合物能有效抑制hemoglobin-pepsin、hemoglobin-proctase、casein-pepsin、casein-proctase、casein-acid protease和hemoglobin-acid protease的活性，其IC50值分别为4.5 nM、6.2 nM、150 nM、290 nM、520 nM和260 nM。此外，对HIV protease也有抑制作用。

NB-360 是一种有效的脑穿透性 BACE1 和 BACE2 抑制剂，对小鼠和人源 BACE1 和 BACE2 的 IC50 分别为 5、5 和 6 nM。 NB-360 对相关的天冬氨酰蛋白酶、胃蛋白酶、组织蛋白酶 E 和组织蛋白酶 D 具有出色的特异性。

Statine is a protease inhibitor that is active against pepsin and other acid proteases.

Imarikiren（又名TAK-272）是一种高效、选择性强且可口服的直接肾素抑制剂，主要用于治疗糖尿病肾病。在hPRA检测中，TAK-272对人肾素的抑制活性极强（IC50 = 2.1 nM），并且对其他天冬酰胺蛋白酶如胃蛋白酶（IC50 > 10 μM）和组织蛋白酶D（IC50 > 10 μM）具有优异的选择性。在大鼠中，TAK-272展示了显著改善的PK形态（F = 25.2%）。通过口服给药（3 和 10 mg kg），TAK-272展现了剂量依赖性的强效持久的降压效果。目前，TAK-272 HCl正处于人类临床试验阶段。

H 256 is a pepsin heptapeptide inhibitor.

LY2811376 是可口服的非肽段β-secretase (BACE1)抑制剂，IC50=239 nM-249 nM，能够降低 Aβ 蛋白的分泌，EC50=300 nM。

Sucralfate is a gastrointestinal protectant that includes sucrose octasulfate . Sucralfate protects gastric epithelial cells against acid- and pepsin-induced damage. Sucrose hexasulfate is a polysulfated disaccharide that is used as a reference standard for sucralfate.

Potent and selective β-secretase (BACE) inhibitor (IC50 values are 10.2 and 20.3 nM for human BACE2 and BACE1, respectively). Displays >5,000-fold selectivity for BACE over other proteases including cathepsin D, pepsin and renin. Inhibits Aβ1-40 and Aβ1-42 production in cells expressing mutated APP. Reduces hippocampal and cortical Aβ and sAPPβ levels in an Alzheimer's disease mouse model.

Polignate Sodium is an Enzyme Inhibitor (Pepsin)

Rennin（亦称Chymosin）是一种蛋白水解酶，与胃蛋白酶有关，其由部分动物胃细胞合成。该酶特异性针对其天然底物K-酪蛋白，在氨基酸残基105和106、苯丙氨酸与甲硫氨酸间的肽键处进行切割，使液态奶转化为半固体状，以便在胃中停留更久，广泛应用于奶酪生产中。

H-Pro-Thr-Glu-Phe-p-nitro-Phe-Arg-Leu-OH 是一种水溶性多肽，可用作组织蛋白酶 D、胃蛋白酶及其前体的底物，并在生化分析中具有潜在应用价值。

胃抑制肽(GIP) (1-42)是一种内源性的42氨基酸肽类肠促素激素，能诱导胰岛素分泌。该激素在肠道神经内分泌K细胞和颌下腺中表达，并在餐后释放到循环中。GIP (1-42)抑制由组胺、五肽和胰岛素引起的胃酸和胃蛋白酶分泌，增加葡萄糖诱导的胰岛素释放，并在大鼠中刺激胃排空。

Dehydroabietic acid (Dehydroabietate) 是 EBV-EA 活化抑制剂。 它是食物衍生化合物，可通过降低血浆葡萄糖、胰岛素水平、血浆甘油三酯 (TG) 和肝 TG 水平来治疗肥胖相关疾病。它的衍生物在动物模型中表现出抗分泌和抗胃蛋白酶作用。

L-Lysine-13C6-15N2 Hydrochloride 是一种 13C 和 15N 标记的 L-Lysine hydrochloride。L-lysine hydrochloride 是人类必需的氨基酸，也是一种常见的食品添加剂，需要通过饮食摄入。L-lysine hydrochloride 可刺激胃蛋白酶与胃酸的分泌，提高胃液分泌功效，促进幼儿生长与发育。

Kinetensin acetate(103131-69-7 free base) 是从经胃蛋白酶处理的人血浆中分离出来的。它是一种神经降压素样肽。