Abstract
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 -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
Original language | English |
---|---|
Pages (from-to) | 4928-4934 |
Journal | Journal of Agricultural and Food Chemistry |
Volume | 52 |
DOIs | |
Publication status | Published - 2004 |
Keywords
- circular-dichroism
- stability
- proteins
- chymotrypsin
- tubers
- solubility
- elkana