Aminopeptidase I from Streptomyces griseus，0.1MG，A9934-.1MG，Sigma

General description

Aminopeptidase I from Streptomyces griseus is a thermostable enzyme with Glu131 and Tyr246 as key active site residues.

Application

Aminopeptidase I from Streptomyces griseus has been used:

• to test the biochar exposure effect on the enzyme activity
• in circular dichroism (CD) spectroscopy studies
• as a positive control in p-nitroanilide degradation assay

Biochem/physiol Actions

Aminopeptidase I from S. griseus has a fairly broad specificity, being able to remove the N-terminal residue of most proteins, except where the penultimate residue is an imino acid. It contains two Zn²⁺ binding sites. Aminopeptidase I from S. griseus is inhibited by 1,10-phenanthroline and is activated six-fold by Ca²⁺, which also stabilizes it against heat inactivation. This monomeric zinc metalloprotein has an isoelectric point (pI) of 5.4.
Aminopeptidase I may also be used as a reagent in the assay of endoprotease activities with a synthetic substrate in a two-stage assay. In the first stage, the endoprotease cleaves a peptide, such as Z-Y-X-Leu-p-nitroanilide, with the X, Y, and Z residues being chosen according to the specificity of the endoprotease.

Packaging

Package size based on protein content.

Physical form

Contains calcium acetate

Preparation Note

Reconstitute in 20 mM tricine, pH 8.0, with 0.05% bovine serum albumin. Dilute the enzyme with the reconstitution buffer to 0.15-0.3 U/mL for a working concentration. Solutions should be prepared fresh prior to use.

Other Notes

One unit will hydrolyze 1.0 μmole of L-leucine-p-nitroanilide to L-leucine and p-nitroaniline per min at pH 8.0, 25 °C and 3.0 mM substrate concentration.
Endopeptidase contaminant: Not more than: 0.01 U/mg protein (as μmole tyrosine equivalent per min released from casein.)