Purification, characterization and subcellular localization of a type-1 ribosome-inactivating protein from the sarcocarp of Cucurbita pepo
Autor: | Shigeo Yoshinari, Minoru Tamura, Yaeta Endo, Shigehiro Koresawa, Hiroshi Sawamoto, Sadaki Yokota |
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Rok vydání: | 1996 |
Předmět: |
Molecular Sequence Data
Ribosome Inactivating Proteins Biology Biochemistry Ribosome Substrate Specificity Cucurbita pepo chemistry.chemical_compound Vegetables Protein biosynthesis Amino Acid Sequence Isoelectric Point N-Glycosyl Hydrolases Plant Proteins chemistry.chemical_classification Molecular mass Ribosome-inactivating protein biology.organism_classification Subcellular localization Molecular biology Amino acid Cell Compartmentation Ricin chemistry Ribosome Inactivating Proteins Type 1 Ribosomes |
Zdroj: | European journal of biochemistry. 242(3) |
ISSN: | 0014-2956 |
Popis: | The flesh of the fruit of Cucurbita pepo contains a type-1 ribosome-inactivating protein (RIP), which we named pepocin. Pepocin was purified to apparent homogeneity by acid fractionation, ion-exchange chromatography and adsorption chromatography. The protein was found to have a molecular mass of 26 kDa and a PI of about 9.9. It does not contain glycosidic linkages. The protein inhibits protein synthesis in a rabbit-reticulocyte lysate with an IC50 (concentration causing 50% inhibition) of 15.4 pM, and depurinates 28S rRNA in the ribosomes of the lysate in a manner identical to that of ricin A-chain and other RIP. The enzyme is also active on wheat-germ ribosomes and on Escherichia coli ribosomes. The sequence of the N-terminal 20 amino acids of the protein reveals a close relationship to other RIP. Immunoelectron-microscopic localization of pepocin in the sarcocarp shows that the protein is predominantly localized in intercellular spaces. In addition, the immunolocalized signals are observed in leaf intercellular spaces. |
Databáze: | OpenAIRE |
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