Biological Product Characterization FAQ Summary
• How to design drugs based on the structure of target proteins?
In the drug development process, the structure of the target protein is crucial for drug design. The basic process of drug design based on the structure of target proteins includes: identification and structural determination of target proteins, computer-aided drug design, compound screening and optimization, and in vitro and in vivo pharmacodynamic testing.
The steps to operate a high-performance liquid chromatography (HPLC) instrument are as follows: power on and prepare, set system parameters, system equilibration, sample injection, data collection, end of experiment and cleaning, power off.
• Can different species within the same genus be used as reference genomes?
Different species within the same genus can be used as reference genomes. When a reference genome for the target species is lacking, genomes of species that are closely related to the target species are typically chosen as references. This is because they share similar genetic backgrounds and evolutionary histories, and their genome structures may be similar to that of the target species. However, the accuracy of this approach can be affected by genetic differences among species. Therefore, ideally, the reference genome of the target species should be used.
• Can you provide a detailed gene knockout research method?
Gene knockout is an important method in biology used to study the function of specific genes. It involves specifically deleting or modifying the target gene and then observing the phenotypic changes in the organism. This method primarily describes the process of gene knockout using the CRISPR/Cas9 system.
• What is the principle of HPLC separation?
HPLC is a chromatographic separation technique that achieves separation based on the differences in interactions between the components in the sample, the mobile phase, and the stationary phase.
• Is there an amino signal in the hydrogen spectrum if glucosamine exists?
The hydrogen spectrum of glucosamine will have an amino signal, which typically appears in the range of δ 3-4 ppm, but the exact position and intensity may vary due to solvent and environmental factors.
In HPLC analysis of monosaccharides, the unknown peak that appears after the fucose peak may be galactose, mannose, or glucose. Its composition can be determined by comparing with standard samples, mass spectrometry analysis, or adjusting chromatographic conditions. Combining these methods can improve identification accuracy.
• A peak appears around 0.9 in the NMR hydrogen spectrum, what could it be?
In NMR, the chemical shift located at approximately 0.9 ppm is typically associated with alkyl hydrogen atoms. More specifically, signals in this region are generally related to the hydrogen atoms of methyl (CH3) groups, especially those methyl groups located at the end of saturated alkane chains.
The presence of a large amount of black granular substances in transmission electron microscope (TEM) detection may be related to issues such as sample preparation, sample contamination, the inherent characteristics of the sample, and imaging parameters. This issue can be addressed by optimizing the sample preparation process and adjusting imaging parameters.
• How to perform peptide mapping experiments?
The following are the basic steps for peptide mapping experiments for your reference: 1. Sample preparation Protein extraction: Choose a suitable extraction method (such as cell lysis, ultrasonic disruption, etc.) to extract the target protein from the sample. Protein purification: If necessary, purify the protein using methods such as gel filtration, ion exchange chromatography, or affinity chromatography. 2. Protein digestion Enzyme selection: Commonly used protein enzymes include trypsin, chymotrypsin, Lys-C, etc. Digestion conditions: Select appropriate buffer and conditions (such as temperature, pH) based on the characteristics of the enzyme. Typically incubate at 37°C for several hours to overnight. 3. Peptide separation High-performance liquid chromatography (HPLC): Use reverse-phase high-performance liquid chromatography (RP-HPLC) to separate the digestion products. Choose appropriate chromatographic columns and mobile phases to separate based on peptide polarity and size. Gradient elution: Usually use a water-acetonitrile (or water-methanol) gradient elution, where mobile phase A is water + 0.1% trifluoroacetic acid (TFA), and mobile phase B is acetonitrile + 0.1% TFA. 4. Peptide detection Mass spectrometry analysis: Use a mass spectrometer to detect the peptides separated by HPLC. Data analysis: Use mass spectrometry data analysis software (such as Mascot, Proteome Discoverer) for peptide identification and matching. 5. Data interpretation Peptide mapping: Plot the peptide map based on HPLC and mass spectrometry data, showing the retention times and mass spectrometry peaks of each peptide segment.
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