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09:47
The Determination of Protease Specificity in Mouse Tissue Extracts by MALDI-TOF Mass Spectrometry: Manipulating PH to Cause Specificity Changes
Published on: May 25, 2018
Substrate specificity of human carboxypeptidase A6
Peter J Lyons1, Lloyd D Fricker
1Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
The Journal of Biological Chemistry
|September 22, 2010
Summary
Carboxypeptidase A6 (CPA6) enzyme activity was characterized, revealing preferences for specific amino acids. This research helps understand its role in neurodevelopmental disorders like Duane syndrome.
Area of Science:
- Biochemistry
- Enzymology
- Neuroscience
Background:
- Carboxypeptidase A6 (CPA6) is an extracellular enzyme linked to Duane syndrome, a neurodevelopmental disorder affecting eye muscle innervation.
- CPA6 expression in embryonic chondrocytic and nervous tissues suggests a role in development.
Purpose of the Study:
- To elucidate the enzymatic function and substrate specificity of CPA6.
- To compare CPA6's activity with other carboxypeptidases (CPs).
Main Methods:
- CPA6 was expressed in HEK293 cells and purified.
- Kinetic parameters were determined using synthetic substrates.
- Quantitative peptidomics analyzed CPA6 preferences on neuropeptides.
Main Results:
- CPA6 exhibits a preference for C-terminal large hydrophobic amino acids.
- Small amino acids and histidine showed very weak CPA6 activity.
- Small and acidic P1 residues were found to significantly inhibit CPA6 cleavage.
Conclusions:
- CPA6 displays distinct substrate specificity within the carboxypeptidase family.
- Understanding CPA6 specificity is crucial for its role in Duane syndrome and other developmental processes.
- Comparative analysis reveals a spectrum of specificity across CPA/B subfamily members.
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