Kallikrein 8 (KLK8) Antibody – Mouse Monoclonal

Kallikreins are a subgroup of serine proteases having diverse physiological functions. Growing evidence suggests that many kallikreins are implicated in carcinogenesis and some have potential as novel cancer and other disease biomarkers. This gene is one of the fifteen kallikrein subfamily members located in tandem in a gene cluster on chromosome 19. The encoded protein may be involved in proteolytic cascade in the skin and may serve as a biomarker for ovarian cancer. Alternate splicing of this gene results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2013]

Function: Serine protease which is capable of degrading a number of proteins such as casein, fibrinogen, kininogen, fibronectin and collagen type IV. Also cleaves L1CAM in response to increased neural activity. Induces neurite outgrowth and fasciculation of cultured hippocampal neurons. Plays a role in the formation and maturation of orphan and small synaptic boutons in the Schaffer-collateral pathway, regulates Schaffer-collateral long-term potentiation in the hippocampus and is required for memory acquisition and synaptic plasticity. Involved in skin desquamation and keratinocyte proliferation. Plays a role in the secondary phase of pathogenesis following spinal cord injury. Ref.16

Catalytic activity: Cleavage of amide substrates following the basic amino acids Arg or Lys at the P1 position, with a preference for Arg over Lys. Ref.16

Enzyme regulation: Inhibited by a range of serine protease inhibitors including antipain, aprotinin, leupeptin, benzamidine and soybean trypsin inhibitor. Ref.16

Subunit structure: Interacts with SPINK9. Ref.19

Subcellular location: Secreted. Cytoplasm. Note: Shows a cytoplasmic distribution in the keratinocytes. Ref.18

Tissue specificity: Isoform 1 is predominantly expressed in the pancreas. Isoform 2 is expressed in adult brain and hippocampus. Isoform 1 and isoform 2 are found in fetal brain and placenta. Detected in salivary gland, uterus, thymus, breast, testis and kidney but not in spleen, liver, lung or normal ovarian tissue. Displays an 11.5-fold increase in Alzheimer disease hippocampus compared to controls and is overexpressed in some ovarian carcinomas. Expressed at low levels in normal skin while high levels are found in psoriasis vulgaris, seborrheic keratosis, lichen planus and squamous cell carcinoma skin samples. Expressed in the keratinocytes. Ref.5 Ref.13 Ref.14 Ref.18

Miscellaneous: Expressed at high levels in serum, ascites fluid and tumor cytosol of advanced stage ovarian cancer patients and may serve as a marker of ovarian cancer.

Sequence similarities: Belongs to the peptidase S1 family. Kallikrein subfamily.Contains 1 peptidase S1 domain.

Biophysicochemical propertiesKinetic parameters:KM=0.07 mM for Pro-Phe-Arg-MCA Ref.16KM=0.07 mM for Z-Val-Val-Arg-MCAKM=0.07 mM for Boc-Val-Pro-Arg-MCAKM=0.10 mM for Boc-Leu-Lys-Arg-MCAKM=0.10 mM for Boc-Val-Leu-Lys-MCAKM=0.07 mM for Boc-Phe-Ser-Arg-MCAVmax=7.1 µmol/min/mg enzyme toward Pro-Phe-Arg-MCAVmax=5.4 µmol/min/mg enzyme toward Z-Val-Val-Arg-MCAVmax=3.9 µmol/min/mg enzyme toward Boc-Val-Pro-Arg-MCAVmax=2.6 µmol/min/mg enzyme toward Boc-Leu-Lys-Arg-MCAVmax=1.9 µmol/min/mg enzyme toward Boc-Val-Leu-Lys-MCAVmax=1.6 µmol/min/mg enzyme toward Boc-Phe-Ser-Arg-MCApH dependence:Optimum pH is 8.5. Active from pH 7-10.