Detection of pathological changes of proteins by peptide mapping after protein digestion by use of oriented...

Diagnostic methods for detecting gastric diseases using chymotryptic digestion of pepsin are discussed. Peptide maps can be prepared using reversed-phase high-performance liquid chromatography. Batchwise chromatography by use of membranes with immobilized Tyr(I2) was used for the isolation of pepsin from gastric mucosa extract or from human blood serum. Enzymes immobilized using suitable antibodies or through their sugar moieties can be used for the preparation of peptide maps because such enzymes share good steric accessibility to their active binding sites and possess increased thermal stability. Biospecific adsorption of proteins to immunosorbents combines the simultaneous isolation of these enzymes with their oriented immobilization. Proteins were stabilized by hydrophilization through the attachment of saccharide residues containing galactose residues. These residues could be activated by oxidation using galactose oxidase and subsequently immobilized to hydrazide-containing solid supports.