Lys-N is a
metalloendopeptidase
A metalloendopeptidase is an enzyme that functions as a metalloproteinase
A metalloproteinase, or metalloprotease, is any protease enzyme whose catalytic mechanism involves a metal. An example is ADAM12 which plays a significant role in the fu ...
found in the mushroom ''
Grifola frondosa
''Grifola frondosa'' (also known as hen-of-the-woods, in Japanese, ram's head or sheep's head) is a polypore mushroom that grows at the base of trees, particularly old growth oaks or maples. It is native to China, Europe, and North America.
It ...
'' that cleaves proteins on the amino side of
lysine
Lysine (symbol Lys or K) is an α-amino acid that is a precursor to many proteins. Lysine contains an α-amino group (which is in the protonated form when the lysine is dissolved in water at physiological pH), an α-carboxylic acid group ( ...
residues.
Mass spectrometry
Lys-N is becoming a popular protease used for protein digestion in
proteomics
Proteomics is the large-scale study of proteins. Proteins are vital macromolecules of all living organisms, with many functions such as the formation of structural fibers of muscle tissue, enzymatic digestion of food, or synthesis and replicatio ...
experiments. The combination Lys-N
proteolytic
Proteolysis is the breakdown of proteins into smaller polypeptides or amino acids. Protein degradation is a major regulatory mechanism of gene expression and contributes substantially to shaping mammalian proteomes. Uncatalysed, the hydrolysis o ...
peptides and mass spectrometry sequencing with
ETD creates
tandem mass spectra composed mostly of amino terminal peptide fragment ions.
This fragmentation pattern facilitates the applicability of these spectra for
de novo peptide sequencing In mass spectrometry, de novo peptide sequencing is the method in which a peptide amino acid sequence is determined from tandem mass spectrometry.
Knowing the amino acid sequence of peptides from a protein digest is essential for studying the biolo ...
.
See also
*
Endoproteinase Lys-C
*
Mass spectrometry
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a ''mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used ...
*
Tandem mass spectrometry
Tandem mass spectrometry, also known as MS/MS or MS2, is a technique in instrumental analysis where two or more stages of analysis using one or more mass analyzer are performed with an additional reaction step in between these analyses to increa ...
*
Bottom-up proteomics
Bottom-up proteomics is a common method to identify proteins and characterize their amino acid sequences and post-translational modifications by proteolytic digestion of proteins prior to analysis by mass spectrometry.
BUP techniques can be an a ...
References
External links
* The
MEROPS
MEROPS is an online database for peptidases (also known as proteases, proteinases and proteolytic enzymes) and their inhibitors. The classification scheme for peptidases was published by Rawlings & Barrett in 1993, and that for protein inhibito ...
online database for peptidases and their inhibitors
M35.004Coverage on GenomewebEnzyme entry at SWISS-PROT
{{Portal bar, Biology, border=no
Proteomics
Proteases
EC 3.4.24
Fungal proteins