The MtoZ Biolabs' Papain Inhibitor is supplied as a ready-to-use inhibitor that rapidly suppresses papain and related cysteine protease activities in a single step. By minimizing proteolysis during lysis, it helps preserve protein integrity and provides a more stable starting point for LC-MS/MS-based protein identification and quantification.
Product Overview
During protein extraction and cell lysis, cysteine protease activity can be rapidly released from samples or introduced inadvertently. If papain or papain-like activity is present in the system, target proteins may undergo non-specific proteolysis, directly compromising the reliability of downstream mass spectrometry and immunoassays.
1. Rapid Proteolysis After Lysis Reduces Protein Integrity
Papain has broad substrate tolerance and can continue cleaving proteins throughout lysis, homogenization, clarification, and sample transfer. This leads to loss of full-length proteins, increased fragmentation, and progressive sample degradation over time.
2. Biased MS Quantification and Reduced Reproducibility
Unintended proteolysis reshapes the peptide pool, decreasing the number of consistently detected peptides and increasing missing values. As a result, DIA, TMT, or label-free quantification can become distorted, weakening group comparisons and biological interpretation.
3. Low-Abundance Proteins and Modification-Related Signals Become Masked
Proteolysis generates abundant background peptides that compete for MS/MS sampling and identification, making low-abundance pathway proteins and PTM-related peptides harder to detect and reducing site coverage and interpretability.
4. Sample-to-Sample Variability Complicates Inhibition Strategies
ECM-rich tissues and membrane protein–enriched samples often require stronger lysis conditions or longer processing times. This expands the window for protease activity and increases batch-to-batch variability in degradation.
Advantages
✅ Easy to Use
The ready-to-use format enables direct addition to commonly used lysis buffers for immediate inhibition.
✅ Excellent Compatibility
MtoZ Biolabs' Papain Inhibitor is compatible with downstream workflows including protein quantification, SDS-PAGE, Western blot, Co-IP, and LC-MS/MS.
✅ Preserves Post-Translational Modification Information
By limiting proteolysis during extraction, the inhibitor helps maintain the native PTM landscape and supports subsequent PTM site localization, quantification, and differential analysis.
Technical Support
1. Protocol Downloads
MtoZ Biolabs provides comprehensive experimental protocols and product manuals to help ensure smooth and reproducible workflows. For access to specific documents or detailed instructions, please contact our support team.
2. Customized Service Support
Our experienced scientists offer tailored technical assistance and customized solutions based on your specific research goals, helping you achieve optimal experimental outcomes.
3. FAQ and Expert Assistance
We provide responsive and professional technical support to address your questions efficiently. Our experts are ready to help you identify and resolve experimental challenges quickly and accurately.
