We labeled HBVpreS-lipopeptides http://www.selleckchem.com/products/azd6738.html with radioactive isotopes and

investigated the in vivo distribution in several species. We demonstrate enrichment of only the inhibitory peptides in the liver of mice, rats, and dogs indicating that these animals, although not susceptible to HBV infection, express an HBV-preS-specific receptor. Peptides were produced by solid-phase synthesis using the fluorenylmethoxycarbonyl/t-butyl (Fmoc/tBu) chemistry on an Applied Biosystems 433A peptide synthesizer. Coupling conditions and the attachment of acyl residues were performed as described.23 Purification was achieved by semipreparative reverse-phase high-performance liquid chromatography (RP-HPLC) on a Chromolith SemiPrep RP-18e column INK128 (100 × 10 mm). Analytical analyses were performed on an Agilent 1100 HPLC system using a Chromolith Performance RP-C18e column (100 × 4.6 mm). As eluents, 0.1% trifluoroacetic acid (TFA) in water (eluent A) and 0.1% TFA in acetonitrile (eluent B) were used. Conditions: linear gradient

from 0 to 100% B within 5 minutes; flow rate 4 mL/min; UV absorbance λ = 214 nm. The identity of the peptides synthesized was verified by HPLC-MS (mass spectrometry) analysis (Exactive, Thermo Fisher Scientific). For radiolabeling a 1 mM stock solution of the respective peptide in water/dimethyl sulfoxide (DMSO) was prepared. The peptides were synthesized with an artificially introduced D-tyrosine at the C-terminus. Labeling with 123I, 125I, or 131I was performed by the chloramine-T method.24 The reaction solution was purified by semipreparative HPLC

using a Chromolith Performance RP-18e column (100 × 4.6 mm) applying a linear gradient of 0.1% TFA in water (eluent A) to 0.1% TFA in acetonitrile (eluent B) within 10 minutes; flow rate 2 mL/min; UV absorbance λ = 214; γ-detection. Organ distribution studies were performed in female NMRI mice and in Wistar rats. Experiments were in compliance MCE公司 with the German animal protection laws. 100 μL of the peptide solution was administered subcutaneously in the hindleg or as an intravenous bolus injection into the tail vein. Three animals were sacrificed at each point in time and the radioactivity in peripheral blood, heart, lung, spleen, liver, kidneys, muscle, brain, intestine, and injection site (=tail, after intravenous injection only) was determined: The samples were weighed and the organ-associated radioactivity was quantified in a gamma counter (Berthold LB951G). The organ-associated activity was related to the injected dose (ID) and expressed as a percentage of the injected dose per gram tissue (%ID/g). After injection into anesthetized animals, scintigraphic images were obtained using a γ-camera (Gamma Imager, Biospace, France). The recording time was 5 minutes. Scintigraphic images of monkeys and dogs were performed employing a SPECT/CT camera (Millennium VG Hawkeye Gamma camera, GE Healthcare). The recording time was 10 minutes, matrix: 265 × 265 pixels.