Purification and partial characterization of canine pepsinogen A and B.
OBJECTIVE
To purify and partially characterize various isoforms of canine pepsinogen (PG) from gastric mucosa.


METHODS
Stomachs obtained from 6 euthanatized dogs.


METHODS
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
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.
Suchodolski
Jan S
JS
Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, Texas A&M University, College Station 77843-4474, USA.
Steiner
Jörg M
JM
Ruaux
Craig G
CG
Boari
Andrea
A
Williams
David A
DA
D000595:Amino Acid Sequence; D000818:Animals; D002850:Chromatography, Gel / Q000662:veterinary; D002852:Chromatography, Ion Exchange / Q000662:veterinary; D004285:Dogs / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D005753:Gastric Mucosa / Q000201:enzymology*; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D020116:Pepsinogen A / Q000737:chemistry / Q000302:isolation & purification*; D010435:Pepsinogens / Q000737:chemistry / Q000302:isolation & purification*; D020033:Protein Isoforms; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein
D010435:Pepsinogens; D020033:Protein Isoforms; D020116:Pepsinogen A