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Updated: Aug 9, 2026
Quantification of Proteins Using Peptide Immunoaffinity Enrichment Coupled with Mass Spectrometry
Published on: July 31, 2011
Purification and partial characterization of canine pepsinogen A and B
Jan S Suchodolski1, Jörg M Steiner, Craig G Ruaux
1Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station 77843-4474, USA.
Objective:
To purify and partially characterize various isoforms of canine pepsinogen (PG) from gastric mucosa.
Sample Population:
Stomachs obtained from 6 euthanatized dogs.
Procedure:
Mucosa was scraped from canine stomachs, and a crude mucosal extract was prepared and further purified by use of weak anion-exchange chromatography, hydroxyapatite chromatography, size-exclusion chromatography, and strong anion-exchange chromatography. Pepsinogens were characterized by estimation of molecular weights, estimation of their isoelectric points (IEPs), and N-terminal amino acid sequencing.
Results:
Two different groups of canine PG were identified after the final strong anion-exchange chromatography: PG A and PG B. Pepsinogens differed in their molecular weights and IER Pepsinogen B appeared to be a dimer with a molecular weight of approximately 34,100 and an IEP of 4.9. Pepsinogen A separated into several isoforms. Molecular weights for the various isoforms of PG A ranged from 34,200 to 42,100, and their IEPs ranged from 4.0 to < 3.0. The N-terminal amino acid sequence for the first 25 amino acid residues for PG A and B had good homology with the amino acid sequences for these proteins in other species.
Conclusions And Clinical Relevance:
Canine PG B and several isoforms of canine PG A have been purified. Availability of these PGs will facilitate development of immunoassays to measure PG in canine serum as a potential diagnostic marker for gastric disorders in dogs.
