Description
RP1-Carboxypeptidase-E is a rabbit polyclonal antibody made to the metallopeptidase carboxypeptidase-E. The antibody is made to a synthetic peptide based on the amino end of the catalytic domain of human carboxypeptidase-E. 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
Carboxypeptidase E is a zinc metalloproteinase of the MC clan, in the M14B family of MEROPS designations. CPE was also identified as carboxypeptidase H, due to a limited ability to cleave carboxyterminal histidines, and autoantibodies to carboxypeptidase H were proposed as markers for autoimmune diabetes. In mice a spontaneous mutation (Ser202Pro) in CPE leads to inactivation and degradation of CPE, and leads to a buildup of neuropeptide precursors that have carboxyterminal extensions relative to the mature forms. The mouse that has the Ser202Pro mutation is called fat/fat, and, as the name implies, is obese. The fat buildup is due to the incomplete conversion of proinsulin I and II to mature insulin, which requires the removal of the carboxyterminal arginines. In the fat/fat mice PC1 and PC2 also accumulate in the islets, presumably because the PC inhibitor 7B2 is not fully processed by CPE. Carboxypeptidase E is located in the secretory granules of endocrine and neuroendocrine cells, and is known to process a number of important neuropeptides. The loss of CPE in the fat/fat mouse would have been considered a lethal mutation, but other carboxypeptidases partially compensate, and this observation led to the discovery of carboxypeptidase D. In addition to the obesity phenotype, the CPE null mutant mice have hippocampal neuron damage and memory loss, and damaged islet cell populations. The islet cells undergo apoptosis, thought to be due to ER stress. A combination of proprotein convertases (principally PC2) and CPE act to process the neuropeptides, and the function of CPE is to remove the cartboxyterminal lysine and arginine residues that are left after PC cleavage. Carboxypeptidase E is a member of the CPB group of carboxypeptidases, which show a preference for basic residues on the carboxyterminus, versus the CPA group, which prefers aliphatic residues. Full length CPE is a 476 amino acid protein, with a 16 residue signal sequence followed by a 25 amino acid propeptide region, which ends in a furin-type PC consensus cleavage site. A catalytic domain follows, of the CPB type, and a membrane association region. A shorter form is reported of 364 amino acids, starting at a methionine 113 residues downstream from the long form. The short form starts at the zinc binding site of the catalytic domain, and contains the rest of the CPE sequence. Little is known about relative production levels, activity or distribution of the shorter form. CPE is described as a membrane-associated and a soluble form, with the membrane attachment provided by the carboxyterminal region. 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-Carboxypeptidase-E is a rabbit polyclonal antibody made to the metallopeptidase carboxypeptidase-E. The antibody is made to a synthetic peptide based on the carboxy end of the catalytic domain of human carboxypeptidase-E. 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
Carboxypeptidase E is a zinc metalloproteinase of the MC clan, in the M14A family of MEROPS designations. CPE was also identified as carboxypeptidase H, due to a limited ability to cleave carboxyterminal histidines, and autoantibodies to carboxypeptidase H were proposed as markers for autoimmune diabetes. In mice a spontaneous mutation (Ser202Pro) in CPE leads to inactivation and degradation of CPE, and leads to a buildup of neuropeptide precursors that have carboxyterminal extensions relative to the mature forms. The mouse that has the Ser202Pro mutation is called fat/fat, and, as the name implies, is obese. The fat buildup is due to the incomplete conversion of proinsulin I and II to mature insulin, which requires the removal of the carboxyterminal arginines. In the fat/fat mice PC1 and PC2 also accumulate in the islets, presumably because the PC inhibitor 7B2 is not fully processed by CPE. Carboxypeptidase E is located in the secretory granules of endocrine and neuroendocrine cells, and is known to process a number of important neuropeptides. The loss of CPE in the fat/fat mouse would have been considered a lethal mutation, but other carboxypeptidases partially compensate, and this observation led to the discovery of carboxypeptidase D. In addition to the obesity phenotype, the CPE null mutant mice have hippocampal neuron damage and memory loss, and damaged islet cell populations. The islet cells undergo apoptosis, thought to be due to ER stress. A combination of proprotein convertases (principally PC2) and CPE act to process the neuropeptides, and the function of CPE is to remove the cartboxyterminal lysine and arginine residues that are left after PC cleavage. Carboxypeptidase E is a member of the CPB group of carboxypeptidases, which show a preference for basic residues on the carboxyterminus, versus the CPA group, which prefers aliphatic residues. Full length CPE is a 476 amino acid protein, with a 16 residue signal sequence followed by a 25 amino acid propeptide region, which ends in a furin-type PC consensus cleavage site. A catalytic domain follows, of the CPB type, and a membrane association region. A shorter form is reported of 364 amino acids, starting at a methionine 113 residues downstream from the long form. The short form starts at the zinc binding site of the catalytic domain, and contains the rest of the CPE sequence. Little is known about relative production levels, activity or distribution of the shorter form. CPE is described as a membrane-associated and a soluble form, with the membrane attachment provided by the carboxyterminal region. 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.
