hplatero's ge_interactions [9 articles]

Abstract

The oncoprotein c-Myc must heterodimerize with Max to bind DNA and perform its oncogenic activity. The c-Myc - Max heterodimer binds DNA through a basic helix-loop-helix leucine zipper (b-HLH-zip) motif and it is proposed that leucine zipper domains could, in concert with the HLH regions, provide the specificity and stability of the b-HLH-zip motif. In this context, we have synthesized the peptides corresponding to the leucine zipper domains of Max and c-Myc with a N-terminal Cys-Gly-Gly linker and studied their dimerization ...

Abstract

Basic region-leucine zipper (B-ZIP) proteins homo- or heterodimerize to bind sequence-specific double-stranded DNA. We present circular dichroism (CD) thermal denaturation data on vitellogenin promoter-binding protein (VBP), a member of the PAR subfamily of B-ZIP proteins that also includes thyroid embryonic factor, hepatocyte leukemia factor, and albumin site D-binding protein. VBP does not heterodimerize with B-ZIP domains from C/EBP[alpha], JUND, or FOS. We describe a dominant negative protein, A-VBP, that contains the VBP leucine zipper and an acidic amphipathic protein sequence that ...

Abstract

The effects of interhelical electrostatic repulsions in controlling the dimerization and stability of two-stranded [alpha]-helical coiled-coils have been studied using de novo designed synthetic coiled-coils. A native coiled-coil was synthesized, which consisted of two identical 35-residue polypeptide chains with a heptad repeat QgVaGbAcLdQeKf and a Cys residue at position 2 to allow formation of an interchain 2-2` disulfide bridge. This peptide, designed to contain no intrachain or interchain electrostatic interactions, forms a stable coiled-coil structure at 20 degreesC in benign medium ...

Abstract

Abstract: The E/K coil, a heterodimeric coiled-coil, has been designed as a universal peptide capture and delivery system for use in applications such as biosensors and affinity chromatography. In this design, heterodimer formation is specified through the placement of charged residues at the e and g positions of the heptad repeat. The affinity and stability of the E/K coil has been modified in order to allow a greater range of conditions for association and dissociation by varying the chain length to ...

Abstract

We use a heterodimerizing leucine zipper system to examine the contribution of the interhelical a-a' interaction to dimer stability for six amino acids (A, V, L, I, K, and N). Circular dichroism (CD) spectroscopy monitored the thermal denaturation of 36 heterodimers that generate six homotypic and 30 heterotypic a-a' interactions. Isoleucine (I-I) is the most stable homotypic a-a' interaction, being 9.2 kcal/mol per dimer more stable than the A-A interaction and 4.0 kcal/mol per dimer more stable than either the L-L ...