Lys-N A0210

Description: Lys-N is an innovative protease that specififically hydrolyzes peptide bonds at the N-terminal of lysine residues. This enzyme can be applied for post-translational modifification (PTM) protein research, and it produces more b ions than y ions in the spectrometer. Combing the use of Lys-N with rTrypsin-N gives the best way for protein sequencing.

Physical Appearance: Lyophilized powder

Molecular Weight: 18.4 kDaa

Resuspension Buffer: 50 μM Zinc Acetic buffer or Zinc Sulfate buffer.

Storage Conditions: Store the lyophilized powder at –20°C. Store reconstituted enzyme at -80 °C for up to 30 days.

Shelf life: 12 months at -80 ℃.

Stability: Maximally active in the pH range 7 - 9.

In-Solution Protein Digestion Protocol:

1. Resuspend 20 μg of Mass Spectrum Grade Lys-N in 40 μL resuspension buffer for maximum activity.

2. Add 50 mM ammonium bicarbonate or Tris-HCl (pH 8) to protein mixture (recommended).

3. Add 0.5 μg/μL Lys-N to reach a final enzyme to substrate ratio of 1:30 to digest the samples. Mix well and incubate at 37 °C for 4 hours.

Purity: > 99.5% peak area analyzed by HPLC at 280 nm.

Specificity: < 5% non-specifific cleavage with Eschericha Coli digests (digestion at 37 °C for 4 hours), analyzed by LC-MS/ MS.

Activity: 394 U/mg.

Unit Definition: 1 unit of proteolytic activity towards azocasein is defifined as the amount of enzyme required for halfmaximal OD366 after a 30 min incubation at 37 °C, pH 10, A366, and light path=1cm.

MALDI-TOF Analysis: No impurity peak found of Lys-N, analyzed by MALDI-TOF

LC-MS/MS Analysis: Human serum albumin (HSA) was dissolved, denatured at 37°C for 1 h, diluted at pH 8.0, and incubated with Lys-N for 4 hours. The digest was analyzed by LC-MS/MS. Experimental peptide results match the peptides generated in a theoretical digest of HSA by Lys-N.