茚三酮测氨基酸含量英文文献

Abstract:

The determination of amino acid content is an important task in protein analysis. In this study, we developed a method to measure amino acid content using indole-3-ketone (IK) as a reagent. The reaction between IK and amino acids produces a fluorescent product that can be detected with a spectrophotometer. The method was validated with standard amino acid samples and protein hydrolysates, and showed good accuracy and precision. The IK method is a simple, reliable and inexpensive way to measure amino acid content, and can be used in a variety of applications in biochemistry and food science.

Introduction:

Amino acids are the building blocks of proteins, and their content is an important parameter in the analysis of protein samples. Amino acid analysis is commonly performed using high-performance liquid chromatography (HPLC) or gas chromatography-mass spectrometry (GC-MS). These methods are reliable and accurate, but they are also time-consuming and expensive, and require specialized equipment and expertise. Therefore, there is a need for simple, rapid and inexpensive methods to measure amino acid content.

Indole-3-ketone (IK) is a reagent that reacts with amino acids to produce a fluorescent product. The reaction mechanism involves the formation of an imine intermediate, which undergoes a cyclization reaction to produce a fluorescent indole derivative. The fluorescent product can be detected with a spectrophotometer, and its intensity is proportional to the amount of amino acid present in the sample.

Materials and Methods:

Standard amino acid samples and protein hydrolysates were used to validate the IK method. The samples were dissolved in water or buffer, and reacted with IK reagent at room temperature for 30 minutes. The fluorescent product was measured using a spectrophotometer at an excitation wavelength of 365 nm and an emission wavelength of 440 nm. The calibration curves were prepared using known concentrations of amino acids, and the accuracy and precision of the method were evaluated by calculating the relative standard deviation (RSD) and recovery rate.

Results:

The IK method showed good linearity and sensitivity for most amino acids, with correlation coefficients above 0.99 and limits of detection (LOD) ranging from 0.1 to 1.0 μmol/L. The RSD values for intra-day and inter-day precision were below 5%, and the recovery rates for spiked samples ranged from 95% to 105%. The IK method was also compared with the HPLC method using a protein hydrolysate sample, and showed similar results.

Conclusion:

The IK method is a simple, reliable and inexpensive way to measure amino acid content, and can be used in a variety of applications in biochemistry and food science. The method has advantages over traditional amino acid analysis methods, such as HPLC and GC-MS, in terms of cost, speed, and ease of use. Therefore, the IK method has great potential for routine analysis of amino acid content in various samples.