Biotinylated Human Transferrin Protein, His,Avitag? (MALS verified)

分子別名（Synonym）

Transferrin,TF,DKFZp781D0156,PRO1557,PRO2086

表達(dá)區(qū)間及表達(dá)系統(tǒng)（Source）

Biotinylated Human Transferrin Protein, His,Avitag (TRN-H82E3) is expressed from human 293 cells (HEK293). It contains AA Val 20 - Pro 698 (Accession # P02787).

Predicted N-terminus: Val 20

蛋白結(jié)構(gòu)（Molecular Characterization）

This protein carries a polyhistidine tag at the C-terminus, followed by an Avi tag (Avitag?)

The protein has a calculated MW of 78.8 kDa. The protein migrates as 70-85 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

標(biāo)記（Labeling）

Biotinylation of this product is performed using Avitag? technology. Briefly, the single lysine residue in the Avitag is enzymatically labeled with biotin.

蛋白標(biāo)記度（Protein Ratio）

Passed as determined by the HABA assay / binding ELISA.

內(nèi)毒素（Endotoxin）

Less than 1.0 EU per μg by the LAL method.

純度（Purity）

>90% as determined by SDS-PAGE.

>90% as determined by SEC-MALS.

制劑（Formulation）

Lyophilized from 0.22 μm filtered solution in PBS, pH7.4 with trehalose as protectant.

Contact us for customized product form or formulation.

重構(gòu)方法（Reconstitution）

Please see Certificate of Analysis for specific instructions.

For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

存儲(chǔ)（Storage）

For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Please avoid repeated freeze-thaw cycles.

This product is stable after storage at:

-20°C to -70°C for 12 months in lyophilized state;

-70°C for 3 months under sterile conditions after reconstitution.

背景（Background）

轉(zhuǎn)鐵蛋白也稱(chēng)為血清轉(zhuǎn)鐵蛋白、β-1金屬結(jié)合球蛋白、TF，是控制生物體液中游離鐵水平的鐵結(jié)合血漿糖蛋白。雖然與轉(zhuǎn)鐵蛋白結(jié)合的鐵不到全身鐵的0.1%（4mg），但它是最重要的鐵庫(kù)，周轉(zhuǎn)率最高（25mg/24h）。轉(zhuǎn)鐵蛋白對(duì)Fe（III）的親和力極高（pH 7.4時(shí)為1023 M?1），但隨著pH值降至中性以下而逐漸降低。當(dāng)不與鐵結(jié)合時(shí)，它被稱(chēng)為“脫輔基轉(zhuǎn)鐵蛋白”。在人類(lèi)中，轉(zhuǎn)鐵蛋白由一條含有679個(gè)氨基酸的多肽鏈組成。它是一個(gè)由α螺旋和β折疊組成的復(fù)合物，形成兩個(gè)結(jié)構(gòu)域（第一個(gè)位于N端，第二個(gè)位于C端）N端和C端序列由球形裂片表示，兩個(gè)裂片之間有一個(gè)鐵結(jié)合位點(diǎn)。肝臟是制造轉(zhuǎn)鐵蛋白的主要來(lái)源，但大腦等其他來(lái)源也會(huì)產(chǎn)生這種分子。轉(zhuǎn)鐵蛋白也與先天免疫系統(tǒng)有關(guān)。轉(zhuǎn)鐵蛋白存在于粘膜中并與鐵結(jié)合，從而創(chuàng)造了一個(gè)游離鐵含量低的環(huán)境，阻礙了細(xì)菌在鐵抑制過(guò)程中的存活。炎癥時(shí)轉(zhuǎn)鐵蛋白水平降低。轉(zhuǎn)鐵蛋白的金屬結(jié)合特性對(duì)人體钚的生物化學(xué)有很大影響。轉(zhuǎn)鐵蛋白對(duì)細(xì)菌具有殺菌作用，因?yàn)樗辜?xì)菌無(wú)法獲得Fe3+。碳水化合物缺乏的轉(zhuǎn)鐵蛋白隨著大量乙醇的消耗而在血液中增加，可以通過(guò)實(shí)驗(yàn)室檢測(cè)進(jìn)行監(jiān)測(cè)。