Covalent structure of chicken pepsinogen

Area of Science:

• Biochemistry
• Proteomics
• Enzymology

Background:

• Chicken pepsinogen is a glycoprotein with a single polypeptide chain.
• Its molecular weight (Mr) is 42,074, including a carbohydrate moiety.

Purpose of the Study:

• To elucidate the complete amino acid sequence of chicken pepsinogen.
• To determine its homology with other pepsinogens and classify it.

Main Methods:

• Limited trypsinolysis of modified chicken pepsinogen.
• Secondary fragmentation using CNBr, trypsin, and other proteases.
• Peptide isolation via chromatography and fingerprinting.

Main Results:

• Successfully obtained and characterized eight expected peptides from primary fragmentation.
• Determined the amino acid sequence and identified internal homologies.
• Established high homology with pepsinogens A.

Conclusions:

• Tentatively assigned chicken pepsinogen to the pepsinogen A group (EC 3.4.23.1).
• Sequence data and kinetic properties support this classification.