CTT 多肽

CTTHWGFTLC

H-Cys-Thr-Thr-His-Trp-Gly-Phe-Thr-Leu-Cys-OH (Disulfide bond)

10

97.8

C₅₂H₇₁N₁₃O₁₄S₂

1166.35

固相合成

Matrix metalloproteinase 2 (MMP2 or gelatinase A), MMP9 (gelatinase B) and other MMPs including collagenases, stromelysins, and the membrane-type MMPs belong to a large family of endopeptidases involved in the degradation of extracellular matrix (ECM) proteins constituting the basement membrane barrier as well as cleavage of growth factor precursors, receptor tyrosine kinases, cell adhesion molecules, and other proteins. MMPs are involved in tumor growth, migration, invasion, and metastases as well as angiogenesis and tissue remodeling. Interestingly, MMP9 expression in the stromal cells but not in the breast cancer cells associated with poor prognosis. In an attempt to develop peptide-based gelatinase inhibitors to attenuate cancer progression, an in vitro phage display screen with purified MMP9 using a random peptide (CX5-8C) library was used to identify two cyclic decapeptides (CTTHWGFTLC (CTT) and CRRHWGFEFC) targeting MMP2 and MMP9. These peptides share the HWGF domain. The inhibitory effect of the peptides was analyzed in a 125I-gelatin degradation assay. CTT or CRRHWGFEFC inhibited the MMP9 activity with micromolar IC50 values while the control peptide (GACLRSGRGCGA) showed negligible effect. CTT also inhibited MMP2 with IC50 of 10 uM. CTT inhibits specifically the MMP2 and MMP9 activity while no inhibitory activity against MT1-MMP, MM8 or MM13 was detected. As a further modification, a CTT derived retro inverso peptide (D amino acids except glycine, L-Gly) was generated (cltfGwhttc) and it showed better inhibitory effect against MMP2 than the original CTT in vitro. However, it was not studied further due to its poor water solubility. When the gelatinase targeting CTT peptide was developed for radioimaging, it lost the inhibitory activity after conjugation to 125I, but not when conjugated to Technetium- 99m. Thus, the N-terminus of CTT was modified by the addition of two alanine and one tyrosine residues (AAY-CTT) followed by labeling with 125I (125I-AAY-CTT) to restore the inhibitory activity. The 125I-AAY-CTT as well as the CTT coated 125I-BSA encapsulated liposomes accumulated to the KS1767 Kaposi’s sarcoma tumors following the intravenous injections, unlike their non-targeting controls with some indication of homing also to metastatic lesions in the lung. In another study, CTT peptide conjugated to 64Cu through a DOPA (1,4,7,10-Tetraazacyclododecane- 1,4,7,10) chelator was tested in PET imaging. Even though the Cu (II)- DOTA-CTT inhibited MMP2 and MMP9 activities with binding affinities (EC50) of 8.7 uM and 18.2 uM, respectively, which are very similar to those of the original CTT (13.2 uM and 11.0 uM, respectively), it was not successful in in vivo tumor imaging. Stability and the gelatinase inhibition activity of the CTT peptide was increased by substituting the disulfide bond with an amide bond to form a c(KAHWGFTLD)NH2 peptide (C6). Cy5.5 fluorescein conjugated to the C6 peptide was taken up by MMP-2 expressing glioma cells in vitro and homed to both intratibial PC-3 prostate xenografts and orthotopic U87 glioma xenografts in vivo. In addition, C6 peptide conjugated to NOTA (1,4,7,10-Triazacyclononanetriacetic acid) chelator and radiolabeled with 68Ga (68Ga-NOTAC6) showed accumulation of the conjugate in subcutaneous ovarian cancer (SKOV3) xenografts. Several studies have since utilized CTT as an MMP2 inhibitor as vasorelaxant and imaging of gelatinase activity in tumors.

一般情况下， CTT 多肽 粉末应该保存在-20甚至-70摄氏度. CTT 多肽 溶解后应该-70摄氏度分装保存，避免反复冻融. 了解更多细节，请查阅手册:多肽溶解及保存指南

• E.Koivunen et al., Nat. Biotechnol., 17, 768 (1999)

三氟乙酸（TFA）是一种强酸，常用于从固相树脂中裂解合成的多肽，也可用于提高多肽纯化步骤中的HPLC性能。默认情况下，定制的多肽是以冻干的TFA盐的形式交付的，其中TFA的含量可能高达10-45%。

定制多肽中的TFA可能会导致后续检测数据出现无法解释的差异。例如，nM浓度的TFA已被证明会干扰细胞实验，在某些情况下会抑制细胞增殖，而在其他情况下会增加细胞活力。

TFA去除服务推荐用于:

• 将用于细胞试验的多肽
• 将被用作原料药或制成品的多肽
• 含有大量碱性残基的亲水多肽

干品多肽的重量中不仅仅包含多肽，还包含有一些非肽的组份，如水、被吸收的溶剂、配位离子和盐等。肽的净含量是指肽在其中的重量百分比，这个百分比的数值范围很大，可能从50%到90%，取决于纯度、序列以及合成和纯化的方法，不要将肽的净含量和肽的纯度混为一谈，他们是两个完全不同的概念。纯度通常是通过HPLC测定的。纯度定义的是多肽样品中含正确序列的组分的百分比，而肽的净含量是指样品中肽类物质相对于总物质所占的百分比，肽的净含量通常是氨基酸组分分析或紫外分光法测定的，这个信息主要是在一些对肽的浓度很敏感的实验中，对计算肽的浓度是很重要的。