| Purification and Quality Control | The His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns. The purified LCK is greater than 90% homogeneous based on SDS-PAGE analysis and contains no detectable protease, DNase and RNase activity. | | Unit Definition (Activity) | 1 unit equals 1 nanogram of purified protein. | | Applications | 10ng of LCK is sufficient to phosphorylated 1 ug of heat-inactivated nuclear or cytoplasmic extract at 30 C for 30 mins. | | Formulation and Storage | The protein is in 20mM Tris-HCl pH7.9,100mM NaCl, 0.2mM EDTA, 1mM DTT and 20% glycerol. Stored at -70°C before use. Avoid repeated freeze thaw cycles. | | Synonym | Homo sapiens lymphocyte-specific protein tyrosine kinase (LCK), transcript variant 2; LSK; p56lck; pp58lck and YT16. | | Protein Sequence | MGCGCSSHPE DDWMENIDVC ENCHYPIVPL DGKGTLLIRN GSEVRDPLVT YEGSNPPASP
LQDNLVIALH SYEPSHDGDL GFEKGEQLRI LEQSGEWWKA QSLTTGQEGF IPFNFVAKAN
SLEPEPWFFK NLSRKDAERQ LLAPGNTHGS FLIRESESTA GSFSLSVRDF DQNQGEVVKH
YKIRNLDNGG FYISPRITFP GLHELVRHYT NASDGLCTRL SRPCQTQKPQ KPWWEDEWEV
PRETLKLVER LGAGQFGEVW MGYYNGHTKV AVKSLKQGSM SPDAFLAEAN LMKQLQHQRL
VRLYAVVTQE PIYIITEYME NGSLVDFLKT PSGIKLTINK LLDMAAQIAE GMAFIEERNY
IHRDLRAANI LVSDTLSCKI ADFGLARLIE DNEYTAREGA KFPIKWTAPE AINYGTFTIK
SDVWSFGILL TEIVTHGRIP YPGMTNPEVI QNLERGYRMV RPDNCPEELY QLMRLCWKER
PEDRPTFDYL RSVLEDFFTA TEGQYQPQP | | Background | LCK is the designation for the gene encoding lymphocyte protein-tyrosine kinase which has been identified in mouse, where it is coded by chromosome 4, and in man, where molecular analysis by somatic cell hybridization and in situ hybridization indicates that it is coded by the 1p35-p32 segment. (1) Rearrangement of LCK may play a role in the lymphocyte malignancy. The oncogene LCK is the protein-tyrosine kinase that regulates allelic exclusion at the T-cell receptor beta locus. (2) The T-cell antigen receptor plays a crucial role in thymocyte differentiation and T-cell activation. After antigen binding to the TCR, and in concert with engagement of other coreceptors and their associated ligands (such as CD4 (186940) and major histocompatibility complex (MHC) class II, CD28 (186760), B7 (112203), CD8 (186910), and MHC I), signal transduction cascades are activated. Data suggested that deficiency in p56(LCK) expression can produce a severe combined immunodeficiency (SCID) phenotype in humans. (3)TCR stimulation appears to directly activate STAT5, which may participate in the regulation of gene transcription and T-cell proliferation during immunologic responses. (4) | | References | 1. Marth, J. D.et al, . Proc. Nat. Acad. Sci. 83: 7400-7404, 1986.
2. Anderson, S. J. et al., Nature 365: 552-554, 1993.
3. Goldman, F. D.; et al., J. Clin. Invest. 102: 421-429, 1998.
4. Welte, T.; et al., Science 283: 222-225, 1999. |
|
