专肽生物_定制多肽合成服务_多肽合成定制服务_多肽合成厂家_多肽合成公司

BAD (103-127) (human), FAM-labeled 是带 FAM 标签的人 BAD (103-127) (HY-P2468)。BAD (103-127) (human) 是 25-mer Bad 多肽，来自 BAD 的 BH3 结构域，具有拮抗 Bcl-xL 的作用。
BAD (103-127) (human), FAM-labeled is a FAM-labeled human BAD (103-127) (HY-P2468). BAD (103-127) (human), the 25-mer Bad peptide, is derived from the BH3 domain of BAD, can antagonize the function of Bcl-xL[1].

多肽荧光标记由于没有放射性，实验操作简单。因此，目前在生物学研究中多肽荧光标记应用非常广泛，多肽荧光标记方法与荧光试剂的结构有关系，对于有游离羧基的采用的方法与接多肽反应相同，也采用HBTU/HOBt/DIEA方法连接。 在N端标记FITC的多肽需经历环化作用来形成荧光素，通常会伴有最后一个氨基酸的去除，但当有一个间隔器如氨基己酸，或者是通过非酸性环境将目的多肽从树脂上切下来时，这种情况可避免在切割的过程中被TFA切割掉。
        人们利用利用荧光标记的多肽来检测目标蛋白的活性，并将 其发展的高通量活性筛选方法应用于疾病治疗靶点蛋白的药物筛选和药物开发（例如，各种激 酶、磷酸酶、肽酶等）。
        专肽生物能够提供技术成熟的各种荧光标记多肽。
 

下面是一些常见的多肽修饰荧光物质结构：




FITC标记
 

      FITC(异硫氰酸荧光素)具有比较高的活性，我们公司可以通过两种方式将FITC标记于多肽 上：(1) 将FITC标记于赖氨酸（Lys）或被选择性地脱保护的鸟氨酸（ornithine）侧链氨基 上；(2) 将FITC标记于多肽N端氨基。

      当在N端标记时，建议在最后一个氨基和由异硫氰酸酯与氨基反应产生的硫脲键之间引入 烷基间隔器（alkyl spacer），如氨基己酸（Ahx）。链接切割需要酸性环境，在N端标记FITC 的多肽需经历环化作用来形成荧光素，通常会伴有最后一个氨基酸的去除，但当有一个间隔器 如氨基己酸，或者是通过非酸性环境将目的肽从树脂上切下来时，这种情况可避免。空间位阻 被认为是在荧光染料前使用Ahx的主要原因，而不是为什么FITC不能直接偶联在多肽上的原因。

      Ahx或b-Ala均可作为间隔器用于FITC标记的多肽上。

普通荧光修饰

通过Lys侧链氨基连接的荧光修饰

专肽常做的荧光物质的激发光波长和发射光波长。可供参考选择：
 

Definition

BAD is a member of the BCl-2 family of proteins and acts to promote apoptosis by forming heterodimers with the survival proteins BCL-2 and BCLXL, thus preventing them from binding with BAX1.  

Discovery

BAD was originally identified in a yeast two hybrid system that was used to screen for BCL-2 interacting proteins1.

Classification

BAD belongs to the BH3 sub-family of proteins that also includes other pro-apoptotic proteins; BH3 BID, BIK, BLK, HRK, BNIP3 and BIML2.

Structural Characteristics

BAD peptides contain a highly conserved alpha-helical BH3 domain through which they form heterodimers with BCL-2 and BCLXL3.  The BH3 domain is structurally defined as four-turn amphipathic a-helices, containing the sequence motif: Hy-X-X-X-Hy-X-X-X-Sm-D/E-X-Hy4.  This domain is sufficient for pro-apoptotic functions of BAD.

Mode of action

BAD peptides are located on the outer-mitochondrail membrane. Activation of NGF or IL-3 receptors on the mitochondrial membrane mediates the activation of AKT or PKA holoenzyme respectively that result in the phosphorylation of BAD at Ser-136 and 1122,5.  Phosphorylated BAD is translocated to the cytosol by phosphoserine binding protein. Following a death signal BAD is dephosporylated and found in association with BCL-XL-BCL-2 in which form BAD can exert its functions6.

Functions

BCL-2 family proteins that includes BAD play a pivotal role in deciding whether a cell will live or die by apoptosis.  Pro-apoptotic function of BAD is triggered by growth factor deprivation in the cell that results in its dephosphorylation and activation7. Activated BAD binds to BCL-2-BCL-XL and releases BAK and BAX that initiate apoptosis.  Increased BAD protein levels have been found in diseases like myocardial ischemia-reperfusion7.  BAD is also implicated in cancer. In mouse models it has been found that decrease in BAD levels leads to malignancy8.  Interestingly recent studies have shown that the tumor suppressor protein, p53 binds to BAD in response to DNA damage and in turn BAD triggers apoptosis of such cells thus maintaining cell physiology9.

References

1.     Elizabeth Y, Jiping Z, Jennifer J, Boise LH, Craig B, Thompson and Stanley JK, (1995). Bad, a heterodimeric partner for Bcl-xL and Bcl-2, displaces bax and promotes cell death. Cell, 80, Issue 2, 285-91.

2.     Atan G, James M.M, Stanley J.K (1999). BCL-2 family members and the mitochondria in apoptosis. Genes and Development, 13; 1899-1911.

3.     Sabine O, Jose-L D, William H, Julia C, Yan W, Gary W, Steve C, Suzanne W, Lawrence CF, and Tilman O (1997). Structural properties of Human BAD. J Biol. Chem., 372, 49, 30866-892.

4.     Beth L, Sangita S and Guido K (2008). Bcl-2 family members; Dual regulators of apoptosis and autophagy. Autophagy, 4:5, 600-606.

5.     Zha J, Harada H, Yang E, Jockel J, Kormeyer SJ (1996c). Serine phosphorylation of death agonist BAD in response to survival factor results in binding to 14-3-3 not BCL-X(L). Cell, 87:619–628.

6.     Zha J, Harada H, Osipov K, Jockel J, Waksman G, Korsmeyer SJ (1997). BH3 domain of BAD is required for heterodimerization with BCL-XL and pro-apoptotic activity. J. Biol. Chem., 272:24101–24104.

7.     Åsa BG and Roberta AG (2007). Bcl-2 family members and apoptosis, taken to heart. Am J Physiol Cell Physiol., 292:45-51.

8.     Zinkel S, Gross A and Yang E (2006). BCL2 family in DNA damage and cell cycle control. Cell Death and Differentiation, 13, 1351–1359.

9.     Peng J, Wenjing D and Mian W (2007). p53 and BAD: Remote strangers become close friends, Cell Research, 17: 283–285.

Dilraj Lama, et al. Molecular dynamics simulations of pro-apoptotic BH3 peptide helices in aqueous medium: relationship between helix stability and their binding affinities to the anti-apoptotic protein Bcl-X(L). J Comput Aided Mol Des. 2011 May;25(5):413-26. : https://pubmed.ncbi.nlm.nih.gov/21523491/