Structural basis of μ-opioid receptor targeting by a nanobody antagonist.

The μ-opioid receptor (μOR), a prototypical G protein-coupled receptor (GPCR), is the target of opioid analgesics such as morphine and fentanyl. Due to the severe side effects of current opioid drugs, there is considerable interest in developing novel modulators of μOR function. Most GPCR ligands today are small molecules, however biologics, including antibodies and nanobodies, represent alternative therapeutics with clear advantages such as affinity and target selectivity.

Bypassing the Need for Cell Permeabilization: Nanobody CDR3 Peptide Improves Binding on Living Bacteria.

Membrane interaction constitutes to be an essential parameter in the mode of action of entities such as proteins, as well as cell-penetrating and antimicrobial peptides, resulting in noninvasive or lytic activities depending on the membrane compositions and interactions. Recently, a nanobody able to interact with the top priority, multidrug-resistant bacterial pathogen was discovered, although binding took place with fixed cells only. To potentially overcome this limitation, linear peptides corresponding to the complementarity-determining regions (CDR) were synthesized and fluorescently labeled.

Nanobody Loop Mimetics Enhance Son of Sevenless 1-Catalyzed Nucleotide Exchange on RAS.

RAS proteins control various intracellular signaling networks. Mutations at specific locations were shown to stabilize their active guanosine triphosphate (GTP)-bound state, which is associated with the development of multiple cancers. An attractive approach to modulate RAS signaling is through its regulatory guanine nucleotide exchange factor (GEF) son of sevenless 1 (SOS1).

Nature-Inspired Dual Purpose Strategy toward Cell-Adhesive PCL Networks: C(-linker-)RGD Incorporation via Thiol-ene Crosslinking.

In an attempt to mimic nature's ability to adhere cells, PCL is often coated with nature-derived polymers or its surface is functionalized with a cell-binding motif. However, said surface modifications are limited to the material's surface, include multiple steps, and are mediated by harsh conditions. Here, we introduce a single-step strategy toward cell-adhesive polymer networks where thiol-ene chemistry serves a dual purpose.

Propargylamine Amino Acids as Constrained -Substituted Lysine Mimetics.

Herein, alkylated propargylamines are reported as constrained lysine mimetics and constructed in a single step using a copper(I)-catalyzed A-coupling reaction. Using multiple secondary amines, the reaction allowed the generation of a structurally diverse set of -Fmoc protected amino acid derivatives. In addition, the A-reaction was applied on solid phase via the assembly of short model tripeptides.