Product Name
Nα-Benzoyl-DL-arginine 4-nitroanilide hydrochloride, 98%
Certificate of Analysis (COA)
Product Introduction
Nα-Benzoyl-DL-arginine 4-nitroanilide hydrochloride (BAPNA) is a widely used chromogenic substrate for trypsin and trypsin-like serine proteases. It is commonly applied in enzyme activity assays, protease kinetics studies, and inhibitor screening experiments.
During enzymatic hydrolysis, BAPNA releases p-nitroaniline (pNA), which exhibits a strong absorbance at 405 nm. The formation of pNA can be easily monitored using spectrophotometric methods or microplate readers, enabling accurate and sensitive quantification of protease activity.
Due to its reliability, sensitivity, and compatibility with high-throughput formats, BAPNA is broadly used in biochemistry, molecular biology, enzyme engineering, pharmaceutical research, and clinical studies.
Mechanism of Action
BAPNA consists of a benzoyl-arginine peptide structure linked to a p-nitroanilide chromogenic group.
Enzymatic Reaction
When hydrolyzed by trypsin or trypsin-like proteases:
- The peptide bond between arginine and p-nitroanilide is cleaved
- p-nitroaniline (pNA) is released
- pNA produces a yellow chromophore
- Absorbance is measured at 405 nm
The increase in absorbance at 405 nm is directly proportional to enzyme activity.
Typical Applications
1. Protease Activity Assays
BAPNA is a standard substrate for measuring the activity of trypsin and trypsin-like serine proteases. During enzymatic cleavage, p-nitroaniline is released, producing a measurable increase in absorbance at 405 nm.
Typical uses include:
- Trypsin enzyme activity determination
- Serine protease functional assays
- Digestive enzyme research
- Protease quantification in biological samples
2. Enzyme Kinetics Studies
- BAPNA is frequently used in enzyme kinetics experiments to determine parameters such as:
- Km (Michaelis constant)
- Vmax (maximum reaction velocity)
- Catalytic efficiency
Because the reaction produces a stable chromogenic signal, BAPNA is suitable for:
- Michaelis–Menten kinetics analysis
- Enzyme catalytic mechanism studies
- Comparative enzyme activity profiling
3. Protease Inhibitor Screening
BAPNA is also commonly used for evaluating protease inhibitors. When an inhibitor is present, the hydrolysis of BAPNA is reduced, resulting in a decrease in the rate of absorbance increase at 405 nm.
This makes BAPNA suitable for:
- Serine protease inhibitor screening
- Drug discovery assays
- High-throughput inhibitor testing
- Structure–activity relationship studies
4. Biomedical and Clinical Research
In biomedical research, BAPNA is used to study physiological and pathological processes involving protease activity, including:
- Pancreatic enzyme activity analysis
- Digestive disorder research
- Inflammation-related protease studies
- Microbial protease characterization
5.Typical Experimental Platforms
BAPNA can be used in various experimental assay systems, including:
- Spectrophotometric enzyme assays
- Microplate reader assays (96- or 384-well formats)
- Continuous kinetic monitoring
- High-throughput screening platforms
Advantages in Enzyme Assays
- Chromogenic detection with clear signal at 405 nm
- Simple colorimetric readout
- No need for fluorescent instrumentation
- Suitable for continuous kinetic monitoring
- Compatible with microplate assays
- Well-established substrate in trypsin research literature
- Cost-effective for high-throughput screening
Recommended Experimental Conditions
| Parameter |
Recommended Condition |
| Detection Wavelength |
405 nm (p-nitroaniline detection) |
| Detection Type |
Colorimetric spectrophotometric assay |
| Buffer Systems |
Tris-HCl, Phosphate buffer, HEPES buffer |
| Optimal pH |
Typically pH 7.5–8.5 |
| Temperature |
25°C–37°C depending on enzyme source |
| Assay Format |
Spectrophotometric assays, Microplate reader assays, Enzyme kinetics studies, Protease inhibitor screening |
Optimization may be required depending on enzyme source and experimental conditions.
Related Research Areas
Researchers working in the following areas may benefit from this product:
- Protease enzymology
- Digestive enzyme research
- Serine protease inhibitor screening
- Enzyme kinetics analysis
- Pharmaceutical discovery
- Biochemical assay development