A Kunitz-type proteinase inhibitor with differential solubility during the development of potato (Solanum tuberosum L.) tubers

Autor:	Yoshio Kikuta, T. Itoh, Cristina Mitsumori, Kazutoshi Yamagishi
Rok vydání:	1996
Předmět:	chemistry.chemical_classification Tubercle food and beverages Vacuole Protein aggregation Biology biology.organism_classification Solanum tuberosum Amino acid Enzyme Biochemistry chemistry Plant protein Agronomy and Crop Science Solanaceae Food Science
Zdroj:	Potato Research. 39:493-505
ISSN:	1871-4528 0014-3065
DOI:	10.1007/bf02358468
Popis:	Two potato (Solanum tuberosum L., cv. Irish Cobbler) Kunitz-type proteinase inhibitors (PKPI) were previously described to be present in the soluble fraction of proteins from tubers in the early stages of development. One of them became insoluble in mature tubers, being extractable from this material in presence of urea. Amino acid sequencing showed that the soluble and insoluble PKPI were identical to each other. Also, immunolocalization using the protein A-gold method showed that both proteins were present inside the vacuole in free (intravacuolar space) and aggregated forms. The density of PKPI in the vacuolar protein aggregates increased from developing to mature tubers. showing that the soluble-insoluble state of this protein is related to the aggregation levels. Purified PKPI precipitated in vitro. mainly in presence of high calcium concentrations and low pH, but this precipitated form was not as stable as aggregates found in vivo. Based on the results obtained, a model of PKPI insolubilization in vivo is discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::4c0350d90ee90ccb75423e69085c8dba https://doi.org/10.1007/bf02358468 Zobrazit plný text záznamu Full text from SpringerLink