Structural characterization of potato protease inhibitor I (cv. Bintje) after expression in Pichia pastoris

article
In the present study the structural properties of potato protease inhibitor 1 (PI-1) were studied as a function of temperature to elucidate its precipitation mechanism upon heating. A cDNA coding for PI-1 from cv. Bintje was cloned and expressed in Pichia pastoris. Using the recombinant PI-1 it was suggested that PI-1 behaves as a hexameric protein rather than as a pentamer, as previously proposed in the literature. The recombinant protein seems either to have a predominantly unordered structure or to belong to the β-II proteins. Differential scanning calorimetry analysis of PI-1 revealed that its thermal unfolding occurs via one endothermic transition in which the hexameric PI-1 probably unfolds, having a dimer instead of a monomer as cooperative unit. The transition temperature for the recombinant PI-1 was 88 °C. Similar results were obtained for a partially purified pool of native PI-1 from cv. Bintje. Molecular Sequence Numbers: GENBANK: AY496262; Chemicals / CAS: proteinase inhibitor, 37205-61-1; Plant Proteins; Protease Inhibitors; Recombinant Proteins
TNO Identifier
237906
ISSN
00218561
Source
Journal of Agricultural and Food Chemistry, 52(15), pp. 4928-4934.
Pages
4928-4934
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