Merck, 11420488001, Endoproteinase Asp-N Sequencing Grade

General description
The wild type of Pseudomonas fragi segregates a metalloprotease, which cleaves peptide bonds N-terminally at small hydrophilic amino acids. A mutant of this strain produces the Endoproteinase Asp-N Sequencing Grade, which is isolated as a highly purified and specific protease.
Application
Use Endoproteinase Asp-N Sequencing Grade for protein structure analysis and sequence analysis.
Biochem/physiol Actions
Endoproteinase Asp-N Sequencing Grade is a metalloprotease. In phosphate, acetate, or Tris buffers at pH 6.0–8.5, it specifically cleaves peptide bonds N-terminally at aspartic and cysteic acid. If cysteine is reduced or alkylated, only -↓-Asp-X is cleaved.
The specificity of Endoproteinase Asp-N Sequencing Grade is verified with glucagon as a substrate. High concentrations of Endoproteinase Asp-N Sequencing Grade (1 part by weight enzyme with 10 parts by weight glucagon) are incubated to detect traces of impurities like contaminating proteases.
Heat inactivation: The protease is stopped by boiling for 5 minutes.
Preparation Note
Working concentration: 2 μg /50 μl double-dist. water
One vial (= 2 μg enzyme) is dissolved in 50 μl double-dist. water resulting in a buffer concentration of 10 mM Tris-HCl pH 7.5.
Working solution: Recommended solvent is double-distilled water.
Storage conditions (working solution): -15 to -25 °C
A solution in double-dist. water is stable for 1 week at maximum at 2 to 8 °C and for about 1 month at -15 to -25 °C; repeated thawing should be avoided.
Lyophilized Endoproteinase Asp-N sequencing grade is reconstituted in 50 μl double-dist. water. This results in a buffer concentration of 10 mM Tris-HCl, pH 7.5. In order to avoid autolysis the incubation temperature should not exceed 37 °C.
Other Notes
For life science research only. Not for use in diagnostic procedures.