Related Experiment Videos
Human cathepsin V functional expression, tissue distribution, electrostatic surface potential, enzymatic
1Department of Human Genetics, Mount Sinai School of Medicine, CUNY, New York 10029, USA. brommd01@doc.mssm.edu
Biochemistry
|February 25, 1999
Summary
Cathepsin V, a human cysteine protease, shows unique substrate specificity and pH stability, differing from Cathepsin L. Its distinct molecular surface electrostatics may explain these differences and its evolutionary origin.
Area of Science:
- Biochemistry
- Molecular Biology
- Protease Research
Background:
- Cathepsin V is a human cysteine protease found in the thymus and testes.
- Understanding its properties is crucial for distinguishing it from related proteases like Cathepsin L and S.
Purpose of the Study:
- To characterize the physicokinetic properties of recombinant Cathepsin V.
- To compare its substrate specificity, collagenolytic activity, and pH stability with Cathepsins L and S.
- To investigate the structural basis for its unique characteristics through homology modeling.
Main Methods:
- Expression of recombinant Cathepsin V in Pichia pastoris.
- Determination of autocatalytic activation pH and inhibition by protease inhibitors.
- Analysis of S2P2 subsite specificity using various substrates.
- Assessment of collagenolytic activity and pH stability.
- Homology modeling to analyze molecular surface electrostatic potentials.
Main Results:
- Recombinant Cathepsin V is autocatalytically activated at acidic pH and inhibited by cysteine protease inhibitors.
- Its S2P2 subsite specificity is intermediate between Cathepsins S and L, accepting diverse hydrophobic residues.
- Cathepsin V exhibits weak collagenolytic activity, similar to Cathepsin S.
- It shows greater stability at mildly acidic and neutral pH than Cathepsin L but less than Cathepsin S.
- Homology modeling revealed distinct electrostatic potentials on Cathepsin V's surface compared to Cathepsin L, resembling mouse Cathepsin L.
Conclusions:
- Cathepsin V possesses unique substrate selectivity and pH stability profiles attributed to its molecular surface electrostatics.
- These properties suggest an evolutionary divergence from an ancestral Cathepsin L-like precursor via gene duplication, supported by its chromosomal location near Cathepsin L.