The presence of tTF moiety in fusion protein was further confirmed by Western blotting analysis. Labeling Fusion Protein with RBITC According to the manufacture’s protocol, the purified (RGD)3-tTF, tripeptide Arg-Gly-Asp (RGD) (Sigma-Aldrich, Saint Louis, MO, USA), and tissue factor (Prospect, East Brunswick, NJ, USA) were dialyzed against 0.5?M carbonate buffer (pH 9.0) and incubated with rhodamine isothiocyanate B (RBITC, Biochemika) at a molar ratio of 1 1?:?24 for 90?min at room temperature with end-to-end mixing. After incubation, the free RBITC was removed from the labeled (RGD)3-tTF, RGD, and TF by extensive dialysis against PBS pH 7.4. All the above treatments were performed under light-protected conditions. 2.6. Clotting Test WH 4-023 Referring to coagulation experiments of Haubitz and Brunkhorst [21], fresh mouse blood was treated with 3.8% sodium citrate. Then, the blood sample was centrifuged at 4000?r/min, and the plasma was collected and used for further test. Plasma sample was added WH 4-023 to wells of 96-well microplate (30?= 5). The mice in each group were injected with 200?= 5). 50?= 15). 50?represents the number of animals per experimental group. Statistical comparisons between the groups were performed by rank sum test. Differences were considered significant at 0.05. 3. Results 3.1. Identification of Target Fusion Gene of (RGD)3-tTF The tTF gene in size of 657?bp was amplified and annealed with primers P3 containing (RGD)3-4C to obtain the template of fusion gene of (RGD)3-tTF by PCR. Then, the template of fusion gene of (RGD)3-tTF was added with Nco I and Xho I endonuclease sites. The expression vector pET22b(+) made up of (RGD)3-tTF gene was reconstructed and then digested with the Nco I and Xho I restriction enzyme for further identification. The digested products of reconstructed vector were used STMN1 for 1% agarose gel electrophoresis analysis. There was a single 780?bp band which was consistent with the theoretical calculated value of the gene of (RGD)3-tTF (784?bp) (Physique 1(a)). The clone gene sequence was identified of being consistent with target gene nucleotide sequence with ampicillin resistance selection and PCR. Open in a separate window Physique 1 Characterization of fused gene and fusion protein of (RGD)3-TF. (a) PCR products of (RGD)3-tTF-pET22b(+); 1: PCR products of (RGD)3-tTF-pET22b(+) digested by restriction enzyme; 2: PCR products of gene of (RGD)3-tTF; 3: DNA marker. (b) Purification of (RGD)3-tTF. 1 and 2: SDS-PAGE; 3 and 4: Western blot; 1 and 3: (RGD) 3-tTF; 2 and 4: prestained molecular weight standards. (c) Identification of purified (RGD)3-tTf. 1: molecular weight markers; 2: (RGD)3-tTF detected using the anti-TF antibody; 3: purified (RGD)3-tTF detected using the anti-RGD antibody. 3.2. Expression, Purification, and Identification of (RGD)3-tTF The fusion protein of (RGD)3-tTF was expressed by 0.05) but significantly less than that of RGD ( 0.05) (Figure 2(a)). Open in a separate window Physique 2 Bioactivity of (RGD)3-tTF. (a) Clotting time. The clotting time of (RGD)3-tTF was comparable to that of TF but significantly higher than that of RGD; there was no significant difference between (RGD)3-tTF and TF (* 0.05,??** 0.01). (b) Factor X (FX) activation. WH 4-023 At WH 4-023 1? 0.05, ** 0.01). (c) Specific binding to 0.01), and RGD binding with 0.05,??** 0.01). 3.4. F X Activation A series of concentrations of (RGD)3-tTF, TF, and RGD were used for activation analysis. Absorbance at 405?nm was measured after activating FX. (RGD)3-tTF at 1? 0.05), while the activation ability of RGD in corresponding concentration was much less than that of TF and (RGD)3-tTF ( 0.05) (Figure 2(b)). 3.5. Specific Binding with 0.01), and the binding with 0.01). At 0.2? 0.05)??(Physique 2(c)). 3.6. Tracing of (RGD)3-tTF In Vivo One hour after intravenously.