Hedgehog proteins create a dynamic cholesterol interface.

During formation of the Hedgehog (Hh) signaling proteins, cooperative activities of the Hedgehog INTein (Hint) fold and Sterol Recognition Region (SRR) couple autoproteolysis to cholesterol ligation. The cholesteroylated Hh morphogens play essential roles in embryogenesis, tissue regeneration, and tumorigenesis. Despite the centrality of cholesterol in Hh function, the full structure of the Hint-SRR ("Hog") domain that attaches cholesterol to the last residue of the active Hh morphogen remains enigmatic.

Publisher Correction: Dual roles of the sterol recognition region in Hedgehog protein modification.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Dual roles of the sterol recognition region in Hedgehog protein modification.

Nature provides a number of mechanisms to encode dynamic information in biomolecules. In metazoans, there exist rare chemical modifications that occur in entirely unique regimes. One such example occurs in the Hedgehog (Hh) morphogens, proteins singular across all domains of life for the nature of their covalent ligation to cholesterol.

Native top-down mass spectrometry provides insights into the copper centers of membrane-bound methane monooxygenase.

Aerobic methane oxidation is catalyzed by particulate methane monooxygenase (pMMO), a copper-dependent, membrane metalloenzyme composed of subunits PmoA, PmoB, and PmoC. Characterization of the copper active site has been limited by challenges in spectroscopic analysis stemming from the presence of multiple copper binding sites, effects of detergent solubilization on activity and crystal structures, and the lack of a heterologous expression system. Here we utilize nanodiscs coupled with native top-down mass spectrometry (nTDMS) to determine the copper stoichiometry in each pMMO subunit and to detect post-translational modifications (PTMs).

Fluorescent gold nanoclusters for efficient cancer cell targeting.

Well-known surface properties of gold nanoparticles (AuNPs) offer easy surface modification with desired biomolecule, thus enabling them to be used for targeting and imaging of cancer cells/tissues. However, targeting and imaging capability come through after synthesis coating of AuNPs' surface with targeting or imaging molecules. Attempts have been made to conjugate both imaging and targeting molecules over the AuNPs, but have seen limited success.

Cu-specific CopB transporter: Revising P-type ATPase classification.

The copper-transporting P-ATPases, which play a key role in cellular copper homeostasis, have been divided traditionally into two subfamilies, the P-ATPases or CopAs and the P-ATPases or CopBs. CopAs selectively export Cu whereas previous studies and bioinformatic analyses have suggested that CopBs are specific for Cu export. Biochemical and spectroscopic characterization of CopB (CopB) show that, while it does bind Cu, the binding site is not the prototypical P-ATPase transmembrane site and does not involve sulfur coordination as proposed previously.

ATP-enhanced peroxidase-like activity of gold nanoparticles.

Gold nanoparticles (AuNPs) are known to possess intrinsic biological peroxidase-like activity that has applications in development of numerous biosensors. The reactivity of the Au atoms at the surface of AuNPs is critical to the performance of such biosensors, yet little is known about the effect of biomolecules and ions on the peroxidase-like activity. In this work, the effect of ATP and other biologically relevant molecules and ions over peroxidase-like activity of AuNPs are described.

YC-1 binding to the β subunit of soluble guanylyl cyclase overcomes allosteric inhibition by the α subunit.

Soluble guanylate cyclase (sGC) is a heterodimeric heme protein and the primary nitric oxide receptor. NO binding stimulates cyclase activity, leading to regulation of cardiovascular physiology and making sGC an attractive target for drug discovery. YC-1 and related compounds stimulate sGC both independently and synergistically with NO and CO binding; however, where the compounds bind and how they work remain unknown.

Crystal structure of the Alpha subunit PAS domain from soluble guanylyl cyclase.

Soluble guanylate cyclase (sGC) is a heterodimeric heme protein of ≈ 150 kDa and the primary nitric oxide receptor. Binding of NO stimulates cyclase activity, leading to regulation of cardiovascular physiology and providing attractive opportunities for drug discovery. How sGC is stimulated and where candidate drugs bind remains unknown.