CD4 蛋白, Human (365a.a, HEK293, His)

CD4 Protein is an integrated membrane glycoprotein that plays various roles in immune responses and defending against internal and external attacks. The alpha-helix structure of CD4 Protein and HIV-1 Vpu can be involved in the binding and degradation of CD4 molecules. CD4 Protein participates in the differentiation/activation, cytokine expression, and cell migration in macrophages or NK cells through a TCR/LCK-independent pathway. CD4 Protein can enhance the host's immune response to viral infections and boost anti-tumor immunity. CD4 Protein, Human (365 a.a, HEK293, His) is a recombinant CD4 protein with a His tag, expressed in HEK293. CD4 Protein, Human (365 a.a, HEK293, His) consists of 365 amino acids, with a molecular weight ranging from 49-58 kDa^[1][2][3].

CD4 Protein 在 T 辅助细胞和细胞毒性淋巴细胞上表达，与 II 类主要组织相容性复合物 (MHC) 抗原相互作用从而介导细胞粘附^[4]。
CD4 Protein 在 NK 细胞内表达可以促进细胞因子 TNF-α 和 γ-IFN 的产生，这些细胞因子作为重要介质从而增强宿主对病毒感染的免疫反应，增强抗肿瘤免疫。此外，CD4 Protein 可以介导 NK 细胞向趋化因子 IL-16 迁移，从而使 NK 细胞迁移到急性炎症部位，增强其先天免疫反应能力^[2]。
CD4 Protein 可以引起 Src 家族激酶、ERK1/2 和 MAPK 依赖性通路的激活，导致单核细胞分化为巨噬细胞，并引起后续 TLR8 表达增加，从而调节先天免疫反应；还可以通过参与 ERK/MAPK/NF-κB 通路诱导钙通量和信号转导^[3]。
CD4 Protein 可以被 Vpu 降解下调，这种蛋白水解活性需要磷酸受体位点 Ser52 和 Ser56 的磷酸化，以及 Vpu 远端细胞质区域存在第二个螺旋结构^[1]。
CD4 Protein 与肿瘤和病毒感染等疾病密切相关^[2]。

CD4 Protein 在 NK 细胞中表达可以促进细胞因子 TNF-α 和 γ-IFN 的表达和 NK 细胞向 CD4 特异性趋化因子 IL-16 迁移^[2]。
CD4 Protein 与人血单核细胞连接触发巨噬细胞分化并增强 HIV 感染^[3]。

CD4 Protein 在内源性 CD4 基因被破坏但人 CD4 转基因的小鼠模型中表达，从而恢复辅助 T 细胞功能^[5]。

Measured by the ability of the immobilized protein to support the adhesion of Hela human cervical epithelial carcinoma cells. The ED₅₀ this effect is 1.335-1.418 μg/mL, corresponding to a specific activity is 705.22-749.06 units/mg.

Human

HEK293

C-6*His

P01730 (K26-W390)

920  [NCBI]

KKVVLGKKGDTVELTCTASQKKSIQFHWKNSNQIKILGNQGSFLTKGPSKLNDRADSRRSLWDQGNFPLIIKNLKIEDSDTYICEVEDQKEEVQLLVFGLTANSDTHLLQGQSLTLTLESPPGSSPSVQCRSPRGKNIQGGKTLSVSQLELQDSGTWTCTVLQNQKKVEFKIDIVVLAFQKASSIVYKKEGEQVEFSFPLAFTVEKLTGSGELWWQAERASSSKSWITFDLKNKEVSVKRVTQDPKLQMGKKLPLHLTLPQALPQYAGSGNLTLALEAKTGKLHQEVNLVVMRATQLQKNLTCEVWGPTSPKLMLSLKLENKEAKVSKREKAVWVLNPEAGMWQCLLSDSGQVLLESNIKVLPTW

49-58 kDa

• 
  Greater than 95% as determined by reducing SDS-PAGE.

无菌粉末.

Lyophilized from a 0.2 μm filtered solution of PBS, pH 7.4 or 20 mM PB, 150 mM NaCl, pH 7.4.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US;may vary elsewhere.

• [1]. Tiganos E, et al. Putative alpha-helical structures in the human immunodeficiency virus type 1 Vpu protein and CD4 are involved in binding and degradation of the CD4 molecule. J Virol. 1997 Jun;71(6):4452-60.  [Content Brief]

  [2]. Bernstein HB, et al. CD4 expression on activated NK cells: ligation of CD4 induces cytokine expression and cell migration. J Immunol. 2006 Sep 15;177(6):3669-76.  [Content Brief]

  [3]. Zhen A, et al. CD4 ligation on human blood monocytes triggers macrophage differentiation and enhances HIV infection. J Virol. 2014 Sep 1;88(17):9934-46.  [Content Brief]

  [4]. Doyle C, et al. Interaction between CD4 and class II MHC molecules mediates cell adhesion. Nature. 1987 Nov 19-25;330(6145):256-9.  [Content Brief]

  [5]. Killeen N, et al. Regulated expression of human CD4 rescues helper T cell development in mice lacking expression of endogenous CD4. EMBO J. 1993 Apr;12(4):1547-53.  [Content Brief]