High luminescent mutant protein obtained by Russian scientists

In order to observe the phenomenon inside cells, scientists often need to use fluorescent protein In the course of studying the changes of cell activities, the research team of the Institute of Biophysics, Siberia branch of Russian Academy of Sciences, through the research on the recombination of the gene encoding the fluorescent protein of marine copepod Daphnia, the modification of the protein and the research on the molecular luminous intensity, obtained the mutant luminous protein whose luminous intensity is 5 times higher than that of natural Daphnia for the first time   In some cases, it is very difficult to use fluorescent protein to monitor the change process inside the cell for a long time, especially if the fluorescent protein of firefly family is used, the fluorescent reaction can only take place under specific conditions, which requires the joint action of oxygen, adenosine triphosphate and magnesium ion However, it is difficult to maintain the effective content of these components in the cell, which makes the fluorescent analysis impossible For a long time However, the fluorescence reaction of the fluorescent protein of copepods is much simpler, which only needs the interaction of calcium and oxygen   Russian researchers cloned the luminescent protein gene of Daphnia elongata, replaced the normal amino acids in the protein, obtained the mutant protein, inserted the nucleotide code of the protein into the circular DNA of the plasmid and made it replicate in the host cell (E.coli), and obtained the luminescent protein through the host cell   For the first time, the researchers found that the fluorescent protein of Daphnia Daphnia lies in the N-terminal part of the fluorescent protein, which does not affect the activity of amino acids If the N-terminal part (amino acid at one end of the protein molecule) is cut off, the intensity of the fluorescence reaction will be enhanced and the luminous intensity will be 5 times of the previous one In addition, the distal amino acid of the Daphnia fluorescent protein is very close to that of the mammalian, which is suitable for the fluorescence analysis of the mammalian cell reaction and transformation process, and has stronger sensitivity than the natural fluorescent protein.