Structural characterization of potato protease inhibitor I (Cv. Bintje) after expression in Pichia pastoris.
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 beta-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 degrees C. Similar results were obtained for a partially purified pool of native PI-1 from cv. Bintje.
van den Broek
Lambertus A M
LA
Centre for Protein Technology TNO-WU, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
Pouvreau
Laurice
L
Lommerse
Gijs
G
Schipper
Bert
B
Van Koningsveld
Gerrit A
GA
Gruppen
Harry
H
D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002942:Circular Dichroism; D004355:Drug Stability; D015870:Gene Expression; D006358:Hot Temperature; D008970:Molecular Weight; D010843:Pichia / Q000235:genetics*; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics*; D011480:Protease Inhibitors / Q000737:chemistry*; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry; D011198:Solanum tuberosum / Q000737:chemistry*
D010940:Plant Proteins; D011480:Protease Inhibitors; D011994:Recombinant Proteins