Aspartic proteinase inhibitors from tomato and potato are more potent against yeast proteinase A than cathepsin D.
The interaction of a variety of aspartic proteinases with a recombinant tomato protein produced in Pichia pastoris was investigated. Only human cathepsin D and, even more potently, proteinase A from Saccharomyces cerevisiae were inhibited. The tomato polypeptide has >80% sequence identity to a previously reported potato inhibitor of cathepsin D. Re-evaluation of the potato inhibitor revealed that it too was more potent (>20-fold) towards yeast proteinase A than cathepsin D and so might be renamed the potato inhibitor of proteinase A. The potency towards yeast proteinase A may reflect a similarity between this fungal enzyme and aspartic proteinases produced by fungal pathogens which attack tomato and/or potatoes.
Cater
Simon A
SA
School of Biosciences, Cardiff University, P.O. Box 911, Cardiff CF10 3US, UK.
Lees
Wendy E
WE
Hill
Jeffrey
J
Brzin
Joze
J
Kay
John
J
Phylip
Lowri H
LH
D000595:Amino Acid Sequence; D016282:Aspartic Acid Endopeptidases / Q000037:antagonists & inhibitors* / Q000737:chemistry; D002402:Cathepsin D / Q000037:antagonists & inhibitors* / Q000737:chemistry; D003001:Cloning, Molecular; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018551:Solanum lycopersicum / Q000235:genetics; D008969:Molecular Sequence Data; D010843:Pichia / Q000235:genetics / Q000378:metabolism; D010957:Plasmids; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D011198:Solanum tuberosum / Q000235:genetics
D004791:Enzyme Inhibitors; D016282:Aspartic Acid Endopeptidases; C022442:aspergillopepsin II; D002402:Cathepsin D