Phytase mutants ykappa-l396v, yeappa-l396v and their coding genes and applications
A technology of phytase and mutants, applied in the field of genetic engineering, can solve problems such as reducing the activity of biological functions
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
Embodiment 1
[0035] Embodiment 1: Obtaining of mutant genes
[0036] Mutants YkAPPA-L396V and YeAPPA-L396V of YkAPPA and YeAPPA were produced by Overlap PCR method. The method uses recombinant plasmids pEASY-T3-YkAPPA and pEASY-T3-YeAPPA containing wild phytase gene as templates, and introduces mutations through two rounds of PCR reactions. The upstream and downstream primers for amplifying the complete coding sequence of the mutant gene have EcoR I and Not I recognition sequences, respectively YkAPPA Forward: 5'-cgcgaattcgcaccgcttgcagcacaatctac-3' and YkAPPA Reverse: 5'-gatgcggccgcttaaatatggcaggctggctcG-3'; YeAPPA Forward: 5' -cgcgaattcgcaccgcttgcagcacaatctac-3' and YeAPPA Reverse: 5' -gatgcggccgcttaaatggcaggctggctcg-3'. The upstream and downstream primers for introducing mutations at specific positions are YkAPPA-L396V Forward: 5’-AGGTG G TGAATTTTTCGGCCTCACCTTA-3’, YkAPPA-L396V Reverse:5’-TAAGGTGAGGCCGAAAAATTCA C CACCT-3', YkAPPA-L396A Forward:5'-CAATGCAGATAAG GCA GATTTGAAAAAc-3', Y...
Embodiment 2
[0037] Example 2: Expression and purification of mutant phytase and wild enzyme in bacteria
[0038] Remove the wild enzyme and mutant enzyme of the signal peptide sequence, insert it into the expression vector pET-22b (+) and transform it into Escherichia coli BL21 (DE3) cells, and inducer IPTG (isopropyl-β- D-galactoside) induces the expression of phytase. The crude enzyme solution was purified by Ni-NTA (nickel-nitrilotriacetic acid) column and DEAE (diethylaminoethyl) column. Both the purified wild enzyme and the mutant enzyme showed a specific protein band of about 46 kDa in SDS-PAGE electrophoresis (data not shown).
Embodiment 3
[0039] Embodiment 3: the protease resistance comparison of mutant phytase and wild enzyme
[0040] Wild enzymes YkAPPA and YeAPPA and mutant enzymes YkAPPA-L396V and YeAPPA-L396V were treated with different concentrations of pepsin (pH2) and trypsin (pH7) at 37°C for 2 hours, respectively, and the remaining enzyme activities in the treated samples were analyzed to study protease Effect on phytase activity. The ratio of protease to phytase is between 1 / 1000 and 1 / 20. Phytase activity was determined using the ferrous sulfate molybdenum blue method. Use 1.5mmol / L sodium phytate as substrate, react at 37°C for 30min, stop the reaction with TCA, and then use chromogenic solution (1% ammonium molybdate tetrahydrate, 3.2% concentrated sulfuric acid, 7.32% ferrous sulfate) color. The control is to add TCA and mix to denature the enzyme before adding the enzyme solution, and the others are the same. Enzyme activity was calculated according to the 700nm light absorbance after color ...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More 


