Sequence-selective DNA recognition and enhanced cellular up-take by peptide–steroid conjugates

Abstract

Several GCN4 bZIP TF models have previously been designed and synthesized. However, the synthetic routes towards these constructs are typically tedious and difficult. We here describe the substitution of the Leucine zipper domain of the protein by a deoxycholic acid derivative appending the two GCN4 binding region peptides through\ud an optimized double azide–alkyne cycloaddition click reaction. In addition to achieving sequence specific dsDNA binding, we have investigated the potential of these compounds to enter cells. Confocal microscopy and flow cytometry show the beneficial influence of the steroid on cell uptake. This unique synthetic model of the bZIP TF thus combines sequence specific dsDNA binding properties with enhanced cell-uptake. Given the unique properties of deoxycholic acid and the convergent nature of the synthesis, we believe this work represents a key achievement in the field of TF mimicry

Taking the Myc out of cancer: toward therapeutic strategies to directly inhibit c-Myc

“…In the case of bHLHZip dimers like c-Myc/Max, the dimerization and DNA-recognition domains are intervened by a loop, making the design of such DNA-binding peptide “tweezers” considerably more challenging. Nevertheless the c-Myc/Max dimer linkage was approached using a steroid-based scaffold to provide structural rigidity and to improve bioavailability, peptide stability and cellular uptake [ 122 , 164 – 166 ]. However, problems such as non-specific DNA binding, incorrect peptide orientation upon DNA binding, and low α -helical stability, were identified .…”

Untapped Opportunities of Resin‐to‐Resin Transfer Reactions (RRTR) for the Convergent Assembly of Multivalent Peptide Conjugates

“…In the context of our research on artificial receptor and minimized protein models, the RRTR methodology seemed attractive towards a faster (library) optimization of such designs . Therefore, we decided to use donor resin 1 for a second time, to assemble a truncated test model derived from the homodimeric GCN4 leucine zipper . A gamma‐aminobutyric acid (GABA) spacer was installed prior to the RRTR step, to alleviate steric constraints typical for our steroid‐based architecture .…”

“…[65][66][67] Therefore, we decidedt ou se donor resin 1 forasecond time, to assemble a truncated test model derived from the homodimeric GCN4 leucine zipper. [68] Ag amma-aminobutyric acid (GABA) spacerw as installed prior to the RRTR step, to alleviates teric constraints typical for our steroid-baseda rchitecture. [69,70] As shown in Figure 3A,a nd B, the second RRTR at the C3-position of 4 also proceeded efficiently,w ith only at race amounto fs tartingm aterial left.…”

Redirection of the Transcription Factor SP1 to AT Rich Binding Sites by a Synthetic Adaptor Molecule

“…In chemical biology, the design and evaluation of artificial transcription factors has become a major activity in recent years. One common approach for achieving sequence specific recognition of DNA relies on the chemically induced dimerization of synthetic helical peptides [1–10] . Molecular biology, on the other hand, has provided access to adaptable proteins such as zinc fingers, [11–13] TALEs [14–16] and dCas9 [17–21] .…”