[en] Highlights: • M6P glycosylation is a key factor for lysosomal enzyme targeting and efficacy of ERT. • M6P glycosylation on rhGAA, the only ERT for Pompe disease, was not fully reported. • This study investigated M6P glycosylation on rhGAA using LC-ESI-HCD-MS/MS. • All M6P glycans constitute 1.0% of the 78 glycans of rhGAA. • Four types of ten M6P glycans and their three attachment sites are newly identified. Myozyme is a recombinant human acid alpha-glucosidase (rhGAA) that is currently the only drug approved for treating Pompe disease, and its low efficacy means that a high dose is required. Mannose-6-phosphate (M6P) glycosylation on rhGAA is a key factor influencing lysosomal enzyme targeting and the efficacy of enzyme replacement therapy (ERT); however, its complex structure and relatively small quantity still remain to be characterized. This study investigated M6P glycosylation on rhGAA using liquid chromatography (LC)–electrospray ionization (ESI)–high-energy collisional dissociation (HCD) tandem mass spectrometry (MS/MS). The glycans released from rhGAA were labeled with procainamide to improve mass ionization efficiency and the sensitivity of MS/MS. The relative quantities (%) of 78 glycans were obtained, and 1.0% of them were glycans containing M6P (M6P glycans). These were categorized according to their structure into 4 types: 3 newly found ones, comprising high-mannose-type M6P glycans capped with N-acetylglucosamine (GlcNAc) (2 variants, 17.5%), hybrid-type M6P glycans (2 variants, 11.2%), and hybrid-type M6P glycans capped with GlcNAc (3 variants, 6.9%), as well as high-mannose-type M6P glycans (3 variants, 64.4%). HCD-MS/MS spectra identified six distinctive M6P-derived oxonium ions. The glycopeptides obtained from protease-digested rhGAA were analyzed using nano-LC-ESI-HCD-MS/MS, and the extracted-ion chromatograms of M6P-derived oxonium ions confirmed three M6P glycosylation sites comprising Asn 140, Asn 233 (newly found), and Asn 470 attached heterogeneously to nine M6P glycans (two types), eight M6P glycans (four types), and seven M6P glycans (two types), respectively. This is the first study of rhGAA to differentiate M6P glycans and identify their attachment sites, despite rhGAA already being an approved drug for Pompe disease.

[en] Organic materials are promising materials for anode electrodes in aqueous hydronium-ion battery due to their flexible of structural, the abundant resources and the tunable electrochemical properties. However, the dissolution of the organic materials in the electrolytes is still inevitable. Polyimide (PI) possesses stable aromatic core, π–π stacking interaction, and increased conjugated system, which are favorable for fast charge transfer kinetics and stable cycling performance of aqueous hydronium-ion battery. Here, the synthesis PI by 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA) and urea is reported. In this work, the capacity of full cell can retain about 67.9% at the current of 5 A• g⁻¹ after charging-discharging over 5000 cycles. Therefore, our studies are suggesting a potential feasibility of these NTCDA-based carbonyl PI as promising organic anode materials for aqueous hydronium-ion battery.

[en] Proton and charge transfers in water solvent have been an issue in the quantum dynamics and energetics of (H₂O)_n clusters. we studied state-to-state correlation curves of the ground and excited states for H₃O dissociating into (H₂O + H). For the dissociation reaction, the molecular orbitals and geometric structures at each internuclear distance were optimized using the restricted open-shell Hartree-Fock method (ROHF), keeping C_2υ symmetry

[en] The diffusion of protons in self-assembled systems is potentially important for the design of efficient proton exchange membranes. In this work, we study proton dynamics in a low-water content, lamellar phase of a sodium-carboxylate gemini surfactant/water system using computer simulations. The hopping of protons via the Grotthuss mechanism is explicitly allowed through the multi-state empirical valence bond method. We find that the hydronium ion is trapped on the hydrophobic side of the surfactant-water interface, and proton diffusion then proceeds by hopping between surface sites. The importance of hydrophobic traps is surprising because one would expect the hydronium ions to be trapped at the charged headgroups. The physics illustrated in this system should be relevant to the proton dynamics in other amphiphilic membrane systems, whenever there exist exposed hydrophobic surface regions.

[en] In this study, we used constrained molecular dynamics techniques to investigate the transport of a hydronium ion across the water liquid/vapor interface. The computed transfer free energy was nearly unchanged as the hydronium ion approached the Gibbs dividing surface. The ion crossed the interface with no substantial minimum free energy, and transport of the hydronium ion involved a change in the solvent composition of the solvation shells around the ion

[en] Rate constants for the important reaction of hydronium ion with hydrated electrons in high-temperature water were reported incorrectly in a previous publication. We correct the previous report and confirm the numbers with new measurements.

[en] We address the question of the composition and spatial distribution of water group plasma in the magnetosphere of Saturn. We suggest that the problem of the coexistence of neutral atomic hydrogen and such a plasma can be resolved if the dominant ion is taken to be H₂O⁺ or H₃O⁺. We also suggest that this ion may provide a means of radiative cooling of the inner magnetosphere plasma which is possibly easier to realize than transport of nitrogen from Titan. As a source for this plasma in the region inward of the icy satellites, we suggest the ring atmosphere. The depleted plasma density in the domain between the Dione-Tethys torus and the ring plane crossing of Voyager may provide an explanation for the survival of the E-ring. Data are presented which indicate that H₂O⁺ or H₃O⁺ is also a favoured candidate in the outer magnetosphere and that it can diffuse without loss through the hot electron gas

[en] An uncharged water-soluble tetra (ω-methoxypolyethyleneoxy)phthalocyanine was characterized by MALDI-TOF mass spectrometry, UV–vis and luminescence measurements. The polyether substituents render water soluble this uncharged phthalocyanine. Relevant changes are observed in emission measurements upon protonation. The phthalocyanine free base and its protonated forms can be switched alternating H₃O⁺ and OH⁻ ions as inputs, being the intensity of the luminescence spectra the output. Binary codes 1 or 0 can be assigned to the high luminescent phthalocyanine free base state or to the low luminescent protonated state, respectively. The read-out procedure is fast and the system is reversible. In addition, the exploiting of the luminescent properties of the present water soluble phthalocyanine could be of relevance also for biological applications (photosensitizers for the photodynamic therapy). Highlights: ► An uncharged water soluble tetra (ω-methoxypolyethyleneoxy)phthalocyanine was characterized. ► Phthalocyanine protonation changes the luminescence output. ► The system can be switched alternating H₃O⁺ and OH⁻ as inputs. ► The read-out procedure is fast and reversible. ► Binary codes are assigned to the high and low luminescent states, respectively.

[en] We optimize force fields for H₃O⁺ and OH⁻ that reproduce the experimental solvation free energies and the activities of H₃O⁺ Cl⁻ and Na⁺ OH⁻ solutions up to concentrations of 1.5 mol/l. The force fields are optimized with respect to the partial charge on the hydrogen atoms and the Lennard-Jones parameters of the oxygen atoms. Remarkably, the partial charge on the hydrogen atom of the optimized H₃O⁺ force field is 0.8 ± 0.1|e|—significantly higher than the value typically used for nonpolarizable water models and H₃O⁺ force fields. In contrast, the optimal partial charge on the hydrogen atom of OH⁻ turns out to be zero. Standard combination rules can be used for H₃O⁺ Cl⁻ solutions, while for Na⁺ OH⁻ solutions, we need to significantly increase the effective anion-cation Lennard-Jones radius. While highlighting the importance of intramolecular electrostatics, our results show that it is possible to generate thermodynamically consistent force fields without using atomic polarizability.

[en] Common polyatomic ions (ArO⁺, NO⁺, H₂O⁺, H₃O⁺, Ar₂⁺, ArN⁺, OH⁺, ArH⁺, O₂⁺) in inductively coupled plasma-mass spectrometry (ICP-MS) are identified using high mass resolution and studied using kinetic gas temperatures (T _gas) determined from a dissociation reaction approach. Methods for making accurate mass measurements, confirming ion identifications, and correcting for mass bias are discussed. The effects of sampler and skimmer cone composition and extraction voltage on polyatomic ion formation are also explored. Neutral species densities at several locations in the extraction interface are estimated and the corresponding effects of the T _gas value are calculated. The results provide information about the origins of background ions and indicate possible locations for their formation or removal