General function of N-terminal propeptide on assisting protein folding and inhibiting catalytic activity based on observations with a chimeric thermolysin-like protease

• Published in: Biochemical and biophysical research communications Vol. 301; no. 4; pp. 1093 - 1098
• Main Authors: Tang, Bing, Nirasawa, Satoru, Kitaoka, Motomitsu, Marie-Claire, Cynthia, Hayashi, Kiyoshi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 21.02.2003; Elsevier
• Subjects: Aeromonas; Aeromonas - enzymology; Aeromonas - genetics; Aeromonas caviae; Bacterial Proteins; Biochemistry, Molecular Biology; C-terminal propeptide; Catalysis; Endopeptidases; Endopeptidases - chemistry; Endopeptidases - genetics; Endopeptidases - metabolism; Enzyme Precursors; Enzyme Precursors - chemistry; Enzyme Precursors - genetics; Enzyme Precursors - metabolism; Inhibition; Life Sciences; Metalloendopeptidases; Metalloendopeptidases - chemistry; Metalloendopeptidases - genetics; Metalloendopeptidases - metabolism; N-terminal propeptide; PA protease; Processing; Protease Inhibitors; Protease Inhibitors - chemistry; Protease Inhibitors - metabolism; Protein Folding; Protein Processing, Post-Translational; Recombinant Fusion Proteins; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Refolding; Vibriolysin; N-terminal propeptide; PA protease; Refolding; C-terminal propeptide; Inhibition; Aeromonas caviae; Vibriolysin; Processing
• DOI: 10.1016/S0006-291X(03)00084-6
• ISSN: 0006-291X

Pro-aminopeptidase processing protease (PA protease) is a thermolysin-like metalloprotease produced by Aeromonas caviae T-64. The N-terminal propeptide acts as an intramolecular chaperone to assist the folding of PA protease and shows inhibitory activity toward its cognate mature enzyme. Moreover, the N-terminal propeptide strongly inhibits the autoprocessing of the C-terminal propeptide by forming a complex with the folded intermediate pro-PA protease containing the C-terminal propeptide (MC). In order to investigate the structural determinants within the N-terminal propeptide that play a role in the folding, processing, and enzyme inhibition of PA protease, we constructed a chimeric pro-PA protease by replacing the N-terminal propeptide with that of vibriolysin, a homologue of PA protease. Our results indicated that, although the N-terminal propeptide of vibriolysin shares only 36% identity with that of PA protease, it assists the refolding of MC, inhibits the folded MC to process its C-terminal propeptide, and shows a stronger inhibitory activity toward the mature PA protease than that of PA protease. These results suggest that the N-terminal propeptide domains in these thermolysin-like proteases may have similar functions, in spite of their primary sequence diversity. In addition, the conserved regions in the N-terminal propeptides of PA protease and vibriolysin may be essential for the functions of the N-terminal propeptide.