Novel carbohydrate structures of cathepsin B from porcine spleen

• Published in: The Journal of biological chemistry Vol. 259; no. 10; pp. 6059 - 6062
• Main Authors: Takahashi, T, Schmidt, P G, Tang, J
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 25.05.1984; American Society for Biochemistry and Molecular Biology
• Subjects: Acetylglucosamine - analysis; Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Animals; Asparagine - analysis; Biological and medical sciences; Carbohydrate Conformation; Carbohydrate Sequence; Carbohydrates - analysis; Cathepsin B; Cathepsins - isolation & purification; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Glycopeptides - isolation & purification; Hydrolases; Macromolecular Substances; Magnetic Resonance Spectroscopy; Spleen - enzymology; Swine; Spleen; High performance; Vertebrata; Mammalia; Molecular structure; Proteinase; Cathepsin B; Liquid chromatography; Artiodactyla; Ungulata; Pig
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(20)82104-8

Two 13-residue glycopeptides were isolated from the digestion of purified porcine spleen cathepsin B by Staphylococcus aureus protease using high performance liquid chromatography. The major peptide, which is about 73% of the total, had the amino acid sequence His-His-Val-Asn(CH2O)-Gly-Ser-Arg-Pro-Pro-Cys-Thr-Gly-Glu. This peptide contains only a single N-acetylglucosamine residue linked to asparagine at the fourth residue by a beta-linkage. The minor peptide had a single amino acid replacement in a sequence otherwise identical to that of the major peptide. A serine was found at residue 10 instead of a half-cystine. The minor peptide also contains different carbohydrates, which were determined using proton NMR to be Man alpha 1—-6 Man beta 1—-4 GlcNAc beta 1—-4(Fuc alpha 1—-6)GlcNAc beta 1—-n Asn. These results suggest that the cathepsin B carbohydrates are processed in vivo by enzymic systems specific to each isozyme.