LCK Protein (GST Tag)

Lymphocyte Cell-Specific Protein-Tyrosine Kinase Protein

LCK Protein Product Information

• Synonym: LCK, RP4-675E8.4, LSK, YT16, p56lck, pp58lck
• Protein Construction: A DNA sequence encoding the human LCK ( NP_001036236.1 ) ( Met 1 - Pro 509 ) was fused with the GST tag at the N-terminus
• Source: Human
• Expression Host: Baculovirus-Insect cells

LCK Protein QC Testing

• Purity: > 90 % as determined by SDS-PAGE
• Bio-activity: Measured by its ability to bind recombinant human CD3E in a functional ELISA.
• Endotoxin: < 1.0 EU per μg of the protein as determined by the LAL method
• Stability: Samples are stable for up to twelve months from date of receipt at -70℃
• Predicted N terminal: Met
• Molecular Mass: The recombinant human LCK/GST chimera consists of 734 amino acids and predicts a molecular mass of 84.4 kDa. It migrates as an approximately 80 kDa band in SDS-PAGE under reducing conditions
• Formulation: Lyophilized from sterile 50mM Tris,100mM NaCl, pH 8.0, 0.5mM GSH , 0.1mM EGTA , 0.1 mM EDTA , 0.5mM PMSF , 10% glycerol
  1. Normally 5 % - 8 % trehalose and mannitol are added as protectants before lyophilization. Specific concentrations are included in the hardcopy of COA.
  2. Please contact us for any concerns or special requirements.
• SDS-PAGE: LCK protein

LCK Protein Usage Guide

• Storage: Store it under sterile conditions at -70℃. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.
• Reconstitution: A hardcopy of COA with reconstitution instruction is sent along with the products. Please refer to it for detailed information.

LCK Protein Description

Tyrosine-protein kinase Lck, also known as Lymphocyte cell-specific protein-tyrosine kinase, p56-LCK, and LCK, is a cell membrane protein which belongs to the protein kinase superfamily and SRC subfamily. LCK is expressed specifically in lymphoid cells. It contains one protein kinase domain, one SH2 domain, and one SH3 domain. LCK is a tyrosine kinase that plays an essential role for the selection and maturation of developing T-cell in the thymus and in mature T-cell function. It is constitutively associated with the cytoplasmic portions of the CD4 and CD8 surface receptors and plays a key role in T-cell antigen receptor (TCR)-linked signal transduction pathways. Association of the TCR with a peptide antigen-bound MHC complex facilitates the interaction of CD4 and CD8 with MHC class II and class I molecules, respectively, and thereby recruits the associated LCK to the vicinity of the TCR/CD3 complex. LCK phosphorylates tyrosines residues within the immunoreceptor tyrosines-based activation motifs (ITAMs) in the cytoplasmic tails of the TCRgamma chains and CD3 subunits, initiating the TCR/CD3 signaling pathway. LCK contributes to signaling by other receptor molecules and associates directly with the cytoplasmic tail of CD2, and upon engagement of the CD2 molecule, LCK undergoes hyperphosphorylation and activation. LCK also plays a role in the IL2 receptor-linked signaling pathway that controls T-cell proliferative response. Binding of IL2 to its receptor results in increased activity of LCK. It is required for the regulation of maturation events that are governed by both pre-TCR and mature alpha beta TCR.

References

1. Holdorf, AD. et al., 2002, Nat Immunol. 3 (3): 259-64.
2. Rao, N. et al., 2002, Proc Natl Acad Sci. USA. 99 (6): 3794-9.
3. Giannini, A. et al., 2004, Mol Cell Biol. 24 (13): 5667-76.
4. Rikova K., et al., 2007, Cell. 131:1190-203.   
5. Oppermann F.S., et al.,2009, Mol. Cell. Proteomics 8:1751-64.