Introduction
Secretory leukocyte protease inhibitor (SLPI) is a secreted protein that protects epithelial tissues from damage by serine proteases. It is found in various secretions, including seminal plasma, cervical mucus, and bronchial secretions. SLPI exhibits a strong affinity for trypsin, leukocyte elastase, and cathepsin G, effectively inhibiting their activity. This inhibitory action contributes to the immune response by safeguarding epithelial surfaces from damage caused by these enzymes. SLPI also demonstrates broad-spectrum antibiotic properties. As an acid-stable protease inhibitor, SLPI effectively neutralizes trypsin, chymotrypsin, elastase, and cathepsin G, preventing elastase-induced harm to oral and mucosal tissues.
Description
This recombinant SLPI protein, expressed in E. coli, is a single, non-glycosylated polypeptide chain consisting of 128 amino acids (specifically, amino acids 26-132). It has a molecular weight of 14 kDa. A 21 amino acid His-Tag is fused to the N-terminus of the SLPI protein to facilitate purification, which is achieved using proprietary chromatographic techniques.
Physical Appearance
A clear, colorless solution that has been sterilized by filtration.
Formulation
The SLPI human solution is provided in a buffer consisting of 20mM Tris-HCl (pH 8.0), 2mM DTT, 0.1M NaCl, and 20% glycerol.
Stability
For short-term storage (2-4 weeks), the solution should be kept at 4°C. For extended storage, it is recommended to freeze the solution at -20°C. The addition of a carrier protein (0.1% HSA or BSA) is advised for long-term storage. To maintain protein integrity, avoid repeated cycles of freezing and thawing.
Purity
The purity of SLPI is greater than 80%, as determined by SDS-PAGE analysis.
Synonyms
Antileukoproteinase, ALK1, ALP, BLPI, HUSI, HUSI-I, MPI, WAP4, WFDC4, WAP four-disulfide core domain protein 4, Protease inhibitor WAP4, Seminal proteinase inhibitor, Mucus proteinase inhibitor.
Amino Acid Sequence
MGSSHHHHHH SSGLVPRGSH MSGKSFKAGV CPPKKSAQCL RYKKPECQSD WQCPGKKRCC PDTCGIKCLD PVDTPNPTRR KPGKCPVTYG QCLMLNPPNF CEMDGQCKRD LKCCMGMCGK SCVSPVKA.
