Ultrasmall gold nanoparticles (diameter about 2nm) were surface-functionalizedw ith cysteine-carrying precision macromolecules. These consistedo fs equence-defined oligo(amidoamine)s (OAAs)w ith either two or six cysteine molecules for binding to the gold surface and either with or withoutaPEG chain (3400 Da). They were characterized by 1 HNMR spectroscopy, 1 HNMR diffusion-ordered spectroscopy (DOSY), small-angle X-ray scattering(SAXS), and high-resolution transmission electron microscopy.T he number of precision macromolecules per nanoparticle was determined after fluorescent labeling by UV spectroscopya nd also by quantitative 1 HNMR spectroscopy.E ach nanoparticle carried between4 0a nd 100 OAA ligands, depending on the number of cysteine units per OAA.T he footprint of each ligandw as about 0.074 nm 2 per cysteinem olecule. OAAs are well suited to stabilize ultrasmall gold nanoparticlesb ys electives urface conjugation and can be used to selectively cover their surface. The presence of the PEG chain considerably increasedt he hydrodynamicd iametero fb oth dissolved macromolecules and macromolecule-conjugated gold nanoparticles.
The enzyme catalysing the removal of N-linked glycans from misfolded glycoproteins in the cytosol is an evolutionary well-conserved glycanase called Peptide:N-glycanase (PNGase; NGLY1 in humans). NGLY1 hydrolyses the amide bond between an Asn and the proximal N-acetylglucosamine (GlcNAc) of the attached N-glycan, thereby converting that particular Asn to Asp. Loss of NGLY1 due to heterozygous-inactivating mutations cause a rare congenital disorder with a multisystemic clinical phenotype. Since the first case report in 2012, extensive research aiming at understanding the pathophysiology of the disease, revealed several crucial biological functions and pathways that involve NGLY1. Here, we highlight the research progress of the past decade. A special emphasis is given to the important role that NGLY1 plays in the transactivation of the transcription factor (NFE2L1; NRF1) that regulates many processes of cellular homeostasis, including proteasome bounce back and oxidative stress response.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.