Description
RP1-Pepsin-A is a rabbit polyclonal antibody made to the aspartic proteinase pepsin-A. The antibody is made to a synthetic peptide based on the aminoterminal end of active human pepsin-A. The antibody has been peptide-affinity purified, concentrated to 1.0 mg/ml, with the addition of 0.05% sodium azide as preservative and 50% glycerol as cryoprotectant.
Use
Pepsin-A (Pepsinogen-A, Pepsinogen-I, Pepsin-I) is an aspartic proteinase secreted as a zymogen (Pepsinogen-A) by the gastric mucosa. Pepsin-A was the first enzyme identified, and one of the first crystallized. The inactive pepsinogen-A is stored in secretory granules, and released on demand to the stomach, where it acts as a promiscuous endopeptidase. Pepsin-A is the archtype member of the clade AA Aspartic peptidases, with the two catalytic aspartic acids arrayed as Asp-Thr-Gly-Thr/SerThe motif, at residues 93 and 277 respectively. The large A1 family of this clade also includes Chymosin, Cathepsin-D, Cathepsin-E, Gastricsin, Napsin, Renin and Memapsins 1 and 2. These aspartic peptidases use the aspartic acid residues to activate water molecules which act as the scissile element in cleaving their substrates. Pepsin-A contains a 15-residue signal sequence followed by a 47-residue propeptide domain. The mature pepsin-A molecule has a two lobed domain structure, with one catalytic residue on each lobe, the result of gene duplication from a historical precursor enzyme. The low pI of Pepsin-A (predicted to be 3.14 for the active enzyme) is designed to work in the acidic stomach environment, and the enzyme is thought to be irreversibly denatured at the more neutral pH outside of the stomach. Elevated levels of pepsin-A have been reported in the sera of gastric cancer patients, and a serum tests for pepsinogen-A and Heliobacter pylori are used to help screen for such cancers. Eradication of H. pylori has been reported to decrease levels of pepsinogen-A, and a causative role is proposed for the bacterial infection and gastric cancer. The ratio of pepsinogen-A to pepsinogen-C have also been studied in gastric cancer patients, and there may be a correlation with the different polymorphisms of pepsinogen-C and cancer. A form of plasmin-A essentially identical to the active plasmin-A of the stomach was found in urine, and termed uropepsin, but it is unclear what the role of the enzyme is in this system. Pepsinogen-A is phosphorylated on a serine between the two catalytic aspartic acid residues, and the phosphorylation is thought to influence pepsin activity. The residues following the phosphoserine are thought to be involved in substrate recognition, and are referred to as the 'flap' motif. Pepsin-A in the serum has been found to be partially inactivated by alpha-2 macroglobulin, but it is unclear how much activity the pepsin in the serum possesses, given their pI. A recommended starting concentration for Western blots is 1:1,000 when using colorimetric substrates such as BCIP/NBT, and 1:5,000 for chemiluminescent substrates. Higher concentrations of antibody may be needed for samples from more distantly related species. FOR RESEARCH USE ONLY; NOT FOR USE IN HUMANS.
Storage
The undiluted antibody solution is stable for 12 months at -20C.
Description
RP2-Pepsin-A is a rabbit polyclonal antibody made to the aspartic proteinase pepsin-A. The antibody is made to a synthetic peptide based on the hinge region mid-molecule, between lobes 1 and 2 of human pepsin-A. The antibody has been peptide-affinity purified, concentrated to 1.0 mg/ml, with the addition of 0.05% sodium azide as preservative and 50% glycerol as cryoprotectant.
Use
Pepsin-A (Pepsinogen-A, Pepsinogen-I, Pepsin-I) is an aspartic proteinase secreted as a zymogen (Pepsinogen-A) by the gastric mucosa. Pepsin-A was the first enzyme identified, and one of the first crystallized. The inactive pepsinogen-A is stored in secretory granules, and released on demand to the stomach, where it acts as a promiscuous endopeptidase. Pepsin-A is the archtype member of the clade AA Aspartic peptidases, with the two catalytic aspartic acids arrayed as Asp-Thr-Gly-Thr/SerThe motif, at residues 93 and 277 respectively. The large A1 family of this clade also includes Chymosin, Cathepsin-D, Cathepsin-E, Gastricsin, Napsin, Renin and Memapsins 1 and 2. These aspartic peptidases use the aspartic acid residues to activate water molecules which act as the scissile element in cleaving their substrates. Pepsin-A contains a 15-residue signal sequence followed by a 47-residue propeptide domain. The mature pepsin-A molecule has a two lobed domain structure, with one catalytic residue on each lobe, the result of gene duplication from a historical precursor enzyme. The low pI of Pepsin-A (predicted to be 3.14 for the active enzyme) is designed to work in the acidic stomach environment, and the enzyme is thought to be irreversibly denatured at the more neutral pH outside of the stomach. Elevated levels of pepsin-A have been reported in the sera of gastric cancer patients, and a serum tests for pepsinogen-A and Heliobacter pylori are used to help screen for such cancers. Eradication of H. pylori has been reported to decrease levels of pepsinogen-A, and a causative role is proposed for the bacterial infection and gastric cancer. The ratio of pepsinogen-A to pepsinogen-C have also been studied in gastric cancer patients, and there may be a correlation with the different polymorphisms of pepsinogen-C and cancer. A form of plasmin-A essentially identical to the active plasmin-A of the stomach was found in urine, and termed uropepsin, but it is unclear what the role of the enzyme is in this system. Pepsinogen-A is phosphorylated on a serine between the two catalytic aspartic acid residues, and the phosphorylation is thought to influence pepsin activity. The residues following the phosphoserine are thought to be involved in substrate recognition, and are referred to as the 'flap' motif. Pepsin-A in the serum has been found to be partially inactivated by alpha-2 macroglobulin, but it is unclear how much activity the pepsin in the serum possesses, given their pI. A recommended starting concentration for Western blots is 1:1,000 when using colorimetric substrates such as BCIP/NBT, and 1:5,000 for chemiluminescent substrates. Higher concentrations of antibody may be needed for samples from more distantly related species. FOR RESEARCH USE ONLY; NOT FOR USE IN HUMANS.
Storage
The undiluted antibody solution is stable for 12 months at -20C.
Description
RP3-Pepsin-A is a rabbit polyclonal antibody made to the aspartic proteinase pepsin-A. The antibody is made to a synthetic peptide based on lobe-2 of human pepsin-A. The antibody has been peptide-affinity purified, concentrated to 1.0 mg/ml, with the addition of 0.05% sodium azide as preservative and 50% glycerol as cryoprotectant.
Use
Pepsin-A (Pepsinogen-A, Pepsinogen-I, Pepsin-I) is an aspartic proteinase secreted as a zymogen (Pepsinogen-A) by the gastric mucosa. Pepsin-A was the first enzyme identified, and one of the first crystallized. The inactive pepsinogen-A is stored in secretory granules, and released on demand to the stomach, where it acts as a promiscuous endopeptidase. Pepsin-A is the archtype member of the clade AA Aspartic peptidases, with the two catalytic aspartic acids arrayed as Asp-Thr-Gly-Thr/SerThe motif, at residues 93 and 277 respectively. The large A1 family of this clade also includes Chymosin, Cathepsin-D, Cathepsin-E, Gastricsin, Napsin, Renin and Memapsins 1 and 2. These aspartic peptidases use the aspartic acid residues to activate water molecules which act as the scissile element in cleaving their substrates. Pepsin-A contains a 15-residue signal sequence followed by a 47-residue propeptide domain. The mature pepsin-A molecule has a two lobed domain structure, with one catalytic residue on each lobe, the result of gene duplication from a historical precursor enzyme. The low pI of Pepsin-A (predicted to be 3.14 for the active enzyme) is designed to work in the acidic stomach environment, and the enzyme is thought to be irreversibly denatured at the more neutral pH outside of the stomach. Elevated levels of pepsin-A have been reported in the sera of gastric cancer patients, and a serum tests for pepsinogen-A and Heliobacter pylori are used to help screen for such cancers. Eradication of H. pylori has been reported to decrease levels of pepsinogen-A, and a causative role is proposed for the bacterial infection and gastric cancer. The ratio of pepsinogen-A to pepsinogen-C have also been studied in gastric cancer patients, and there may be a correlation with the different polymorphisms of pepsinogen-C and cancer. A form of plasmin-A essentially identical to the active plasmin-A of the stomach was found in urine, and termed uropepsin, but it is unclear what the role of the enzyme is in this system. Pepsinogen-A is phosphorylated on a serine between the two catalytic aspartic acid residues, and the phosphorylation is thought to influence pepsin activity. The residues following the phosphoserine are thought to be involved in substrate recognition, and are referred to as the 'flap' motif. Pepsin-A in the serum has been found to be partially inactivated by alpha-2 macroglobulin, but it is unclear how much activity the pepsin in the serum possesses, given their pI. A recommended starting concentration for Western blots is 1:1,000 when using colorimetric substrates such as BCIP/NBT, and 1:5,000 for chemiluminescent substrates. Higher concentrations of antibody may be needed for samples from more distantly related species. FOR RESEARCH USE ONLY; NOT FOR USE IN HUMANS.
Storage
The undiluted antibody solution is stable for 12 months at -20C.
