A basic residue at position 36p of the propeptide is not essential for the correct folding and subsequent autocatalytic activation of prochymosin.

Position 36p in the propeptides of gastric aspartic proteinases is generally occupied by lysine or arginine. This has led to the conclusion that a basic residue at this position, which interacts with the active-site aspartates, is essential for folding and activation of the zymogen. Lamb prochymosin has been shown by cDNA cloning to possess glutamic acid at 36p.

The cysteine protease activity of Colorado potato beetle (Leptinotarsa decemlineata Say) guts, which is insensitive to potato protease inhibitors, is inhibited by thyroglobulin type-1 domain inhibitors.

High levels of protease inhibitors are induced in potato leaves by wounding. These inhibitors, when ingested by Colorado potato beetle (Leptinotarsa decemlineata Say) larvae, induce expression of specific proteolytic activities in the gut. Induced protease activities cannot be inhibited by potato inhibitors and thus enable the insects to overcome this defence mechanism of potato plants.

Potato cysteine proteinase inhibitor gene family: molecular cloning, characterisation and immunocytochemical localisation studies.

Potato cysteine proteinase inhibitors (PCPIs) represent a distinct group of proteins as they show no homology to any other known cysteine proteinase inhibitor superfamilies, but they all belong to the Kunitz-type soybean trypsin inhibitor family. cDNA clones for five PCPIs have been isolated and sequenced. Amino acid substitutions occurring in the limited regions forming loops on the surface of these proteins suggest a further classification of PCPIs into three subgroups.

Jasmonic acid inducible aspartic proteinase inhibitors from potato.

A new cDNA clone coding for an aspartic proteinase inhibitor homologue was isolated from a potato tuber cDNA library. Southern blot analysis was used to study the structural diversity of the aspartic proteinase inhibitor gene family in several species of the Solanaceae. The existence of sequence-homologous genes was confirmed in the genomic DNA of different potato cultivars (Solanum tuberosum L.