Active Recombinant Human Ribonuclease A (RNase A) - 5 mg
Source: Prokaryotic expression.
Host: E. coli
Residues: Lys29~Thr156
Tags: N-terminal His-tag
Traits: Liquid
Concentration: 500μg/mL
Endotoxin Level: <1.0EU per 1μg (determined by the LAL method).
Buffer Formulation: 10mM Tris，15mM NaCl, pH 7.5.
Applications: Cell culture; Activity Assays. (May be suitable for use in other assays to be determined by the end user.)
Predicted isoelectric point: 8.8
Predicted Molecular Mass: 16.1kDa
Accurate Molecular Mass: 18kDa as determined by SDS-PAGE (reducing conditions).
Storage: Avoid repeated freeze/thaw cycles. Store at 2-8 oC for one month. Aliquot and store at -80 oC for 12 months.
Stability Test: The thermal stability is described by the loss rate. The loss rate was determined by accelerated thermal degradation test, that is, incubate the protein at 37oC for 48h, and no obvious degradation and precipitation were observed. The loss rate is less than 5% within the expiration date under appropriate storage condition.
Activity: Ribonuclease A (RNASEA) is a member of the pancreatic-type of secretory ribonucleases, a subset of the ribonuclease A superfamily. RNASE A cleaves RNA on the 3' side of pyrimidine nucleotides. The protein acts to degrade ds-RNA over ss-RNA. The activity of recombinant human RNASEA measured by cleaving yeast RNA. One unit of the enzyme causes an increase in absorbance of 0.001at 260 nm in 15 min when yeast RNA is hydrolyzed at 50°C and pH5.0. Pipette 50ul of respective recombinant human RNASE A dilution into 100ul 0.1M sodium acetate buffer, pH 5.0, then add 150ul of 0.15mg/ml yeast RNA. The blank tube use 50ul ultrapure water instead of enzyme dilution. All the all tubes Incubate at 50°C for 15 minutes. Read A260 versus blank.
Calculation:
Units/mg= 
1000= Absorbance conversion factor with 0.001；
N= Absorbance conversion factor；
15= Time of assay (inminutes)
The specific activity of recombinant human RNASEA is 1.3×10^4 U/mg.