Activators & Inhibitors

As protease inhibitors, serpins have an array of functions including regulating blood clotting, the complement pathway, extracellular matrix remodeling, and cell motility. Serpin G1 is a serine protease inhibitor protein. It is the largest member among the serpin class of proteins. Remarkably, Serpin G1 has a 2-domain structure, unlike most family members. The C-terminal serpin domain is similar to other serpins, and this part of Serpin G1 provides the inhibitory activity. The N-terminal domain is not essential for Serpin G1 to inhibit proteinases and has no similarity to other proteins. The main function of Serpin G1 is the inhibition of the complement system to prevent spontaneous activation. Serpin G1 is an acute phase protein and circulates in blood at levels of around 0.25g/L, whose levels rise 2-fold during inflammation. Although named after its complement inhibitory activity, Serpin G1 also inhibits proteinases of the fibrinolytic, clotting, and kinin pathways. Most notably, Ser

Angiotensinogen is involved in maintaining blood pressure and in the pathogenesis of essential hypertension and preeclampsia. Genetic variations in Angiotensinogen are associated with susceptibility to essential hypertension, and can cause renal tubular dysgenesis, a severe disorder of renal tubular development. Defects in the encoding gene have also been associated with non-familial structural atrial fibrillation, and inflammatory bowel disease.

Serpin A1 is a prototype member of the Serpin superfamily of the serine protease inhibitors. As one of the most abundant proteinase inhibitors in the circulation, it is synthesized in hepatocytes, and to a lesser extent, in macrophages as well as intestinal epithelial cell lines and secreted as the abundant proteinase inhibitor in the circulation whose targets include elastase, plasmin, thrombin, trypsin, chymotrypsin, and plasminogen activator. Point mutations in the native SerpinA1 variants result in Serpin A1 deficiency, and consequently lead to several clinical complications such as pulmonary emphysema, juvenile hepatitis, cirrhosis, and hepatocellular carcinoma. For example, the Z variants (Glu342 to Lys) forms intracellular inclusion bodies, is not secreted, and leads to a severe SerpinA1 deficiency. Accordingly, Serpin A1 deficiency in circulation is associated with emphysema or liver disease.

Cathepsin L is an enzyme. Cathepsin L, a lysosomal endopeptidase expressed in most eukaryotic cells, is a member of the papain-like family of cysteine proteinases. Cathepsin L plays a major role in antigen processing, tumor invasion and metastasis, bone resorption, and turnover of intracellular and secreted proteins involved in growth regulation. Unlike the precursor forms of other papain family members, the 43 kDa pro-cathepsin L itself is secreted from various cells. Pro-cathepsin L is the major excreted protein of malignantly transformed mouse fibroblasts and is also one of the major acidic cysteine proteases in mammalian cells.

Protein Delta Homolog 1 (DLK-1) is a transmembrane protein which contains a signal peptide, an extracellular domain with six tandem epidermai growth factor (EGF)-like domains, a single pass transmembrane domain, and a short cytoplasmic tail. It is found within the stromal cells in close contact to the vascular structure of placental villi, yolk sac, fetal liver, adrenal cortex and pancreas and in the beta cells of the islets of Langerhans in the adult pancreas. In addition, it is detected in some forms of neuroendocrine lung tumor tissue. DLK-1 may have a improtant role in neuroendocrine differentiation.

KRAS Protein, Human, Recombinant (G12C, His) is expressed in E. coli expression system with N-6xHis tag. The predicted molecular weight is 26 KDa and the accession number is AAH13572.1.

KRAS Protein, Human, Recombinant (G12V, His) is expressed in E. coli expression system with N-6xHis tag. The predicted molecular weight is 25-30 KDa and the accession number is AAH13572.1.

Lactotransferrin is a member of the transferrin family that transfer iron to the cells and control the level of free iron in the blood and external secretions. Lactotransferrin is a secreted protein and contains two transferrin-like domains. Lactotransferrin can be cleaved into the following four chains: Kaliocin-1, Lactoferroxin-A, Lactoferroxin-B, and Lactoferroxin-C. Lactoferroxin A, Lactoferroxin B, and Lactoferroxin C have opioid antagonist activity. Lactoferroxin A shows preference for mu-receptors, while Lactoferroxin B and Lactoferroxin C have somewhat higher degrees of preference for kappa-receptors than for mu-receptors. LTF has antimicrobial activity (bacteriocide, fungicide) and is part of the innate defense, mainly at mucoses.

Prostatic Acid Phosphatase (PAP) belongs to the histidine acid phosphatase family. PAP can catalyze the hydrolysis of member of phosphate monoestyers, including phosphorylated protein. PAP can high expression in metastasized prostate cancer, moderately expression level in bone diseases, blood cell disease, and the concentration of PAP is used to monitor and assess the proession of prostate cancer. The optimum PH of PAP is from 4 to 6; its activity can be inhibited by L(+)-tartrate.