Synthesis and Antibody Recognition of Cyclic Epitope Peptides, Together with Their Dimer and Conjugated Derivatives Based on Residues 9−22 of Herpes Simplex Virus Type 1 Glycoprotein D

Abstract

The synthesis of new cyclic peptides comprising the 9-22 epitope (9)LKMADPNRFRGKDL(22) sequence derived from HSV gD-1 is reported. In addition, we describe procedures for the preparation of cyclic peptide dimers and conjugates with an oligotuftsin derivative carrier. The binding of a monoclonal antibody, Mab A16, to the synthesized compounds was determined by enzyme-linked immunosorbent assay. It was demonstrated that cyclization decreased the binding activity of the antibody to the epitope. However, dimerization and conjugation could significantly increase the binding capacity of the cyclic epitope peptides. The attachment site in dimers and conjugates, as well as the topology of the construct, had a significant influence on the antibody recognition, while replacement of Met in position 11 by Nle had no marked effect.

Development of Cyclic NGR Peptides with Thioether Linkage: Structure and Dynamics Determining Deamidation and Bioactivity

“…37 Furthermore chloroacetylated peptides with orthogonal protecting groups on two cysteines are suitable for cyclization and conjugation to a carrier via thioether bond formation in both cases. 38 In accordance with the observations described above, in this study our aim was a) to develop novel thioether linked cyclic NGR-peptides of different ring size (15-18 atoms of the cycle); b) to study the structure -stability (rate of deamidation) relationship of these compounds; c) to verify the rearrangement of NGR to isoDGR by measurement of the time …”

“…The N-terminus of the peptides was chloroacetylated using 5 equiv of chloroacetic acid pentachlorophenyl ester (ClAc-OPcp) that was prepared in our laboratory. 38 The cleaved chloroacetylated peptides were purified by RP-HPLC prior to the cyclization. The thioether bond was formed in 0.1 M Tris buffer (pH 8.1) as follows: the liophylized linear peptides were added to the buffer solution in portions in 2 h. The final peptide concentration was 10 mg/mL in all cases.…”

Seropositivity and Antibody Profiling of Patients Are Dramatically Impacted by the Features of Peptides Used as Immunosorbents: A Lesson from Anti–Citrullinated Protein/Peptide Antibody

“…A fter the development of ELISA in the 70s (1,2), the discovery of the high avidin-biotin affinity (3,4) allowed researchers to precisely manipulate proteins/peptides in numerous ELISA constructs in the 90s (5). Today, although ELISA is used worldwide, for instance to detect and quantify Abs, some studies highlighted the influence of experimental parameters on the outputs of such assay (6)(7)(8)(9)(10), reporting that a small change in the structure of an epitope-presenting peptide could impact its recognition by Abs (11)(12)(13)(14) and thus our perception of the analyzed biological processes. This is particularly important for autoimmune diseases such as rheumatoid arthritis (RA) in which autoantibody profiling, specificity, and titers can be associated with pathophysiology mechanisms and impact diseases diagnosis or therapy management (15)(16)(17)(18)(19)(20).…”

Thallium(III) in Organic Synthesis

“…107 This transformation is often performed in trifluoroacetic acid in the presence of anisole as scavenger. [108][109][110][111][112][113][114] Other conditions reported are TTFA in N-methylpyrrolidone 115 or in N,Ndimethylformamide. 116,117 In addition, thallium(III) chloride has been used in the synthesis of disulfides.…”