A Method for In-Depth Structural Annotation of Human Serum Glycans That Yields Biological Variations

Glycosylation is an important post-translational modification of proteins present in the vast majority of human proteins. For this reason, they are potentially new sources of biomarkers and active targets of therapeutics and vaccines. However, the absence of a biosynthetic template as in the genome and the general complexity of the structures have limited the development of methods for comprehensive structural analysis. Even now, the exact structures of many abundant N-glycans in serum are not known. Structural elucidation of oligosaccharides remains difficult and time-consuming. Here, we introduce a means of rapidly identifying released N-glycan structures using their accurate masses and retention times based on a glycan library. This serum glycan library, significantly expanded from a previous one covering glycans released from a handful of serum glycoproteins, has more than 170 complete and partial structures and constructed instead from whole serum. The method employs primarily nanoflow liquid chromatography and accurate mass spectrometry. The method allows us to readily profile N-glycans in biological fluids with deep structural analysis. This approach is used to determine the relative abundances and variations in the N-glycans from several individuals providing detailed variations in the abundances of the important N-glycans in blood

Fluorescent Recognition of Zn²⁺ by Two Diastereomeric Salicylaldimines: Dramatically Different Responses and Spectroscopic Investigation

Fluorescence responses of two BINOL-based diastereomeric salicylaldimines toward a variety of metal cations have been studied in methanol solution. It is revealed that both compounds show great fluorescence enhancements in the presence of Zn²⁺ but not with any other metal ions. Moreover, these two diastereomers exhibit dramatically different responses toward Zn²⁺ under the same conditions. That is, one can produce much stronger fluorescence enhancement also at a longer wavelength than the other. This fluorescence recognition of Zn²⁺ also shows distinctive color changes under a UV lamp. Mass and NMR spectroscopic analyses have been used to study the mechanism, which indicates the formation of 2+<i>n</i>Zn²⁺ complexes (<i>n</i> = 2, 3). This work has shed new light on the mechanism of an enantioselective fluorescent recognition of chiral amines promoted by Zn²⁺

In-Depth Method for the Characterization of Glycosylation in Manufactured Recombinant Monoclonal Antibody Drugs

The glycosylation in recombinant monoclonal antibody (rMab) drugs is a major concern in the biopharmaceutical industry as it impacts the drugs’ many attributes. Characterization is important but complicated by the intricate structures, microheterogeneity, and the limitations of current tools for structural analysis. In this study, we developed a liquid chromatography–mass spectrometry (LC–MS) N-glycan library based on eight commercial rMab drugs. A library of over 70 structures was developed for the rapid characterization of rMab. N-Glycans were separated on a porous graphitized carbon (PGC) column incorporated on a chip and then analyzed by an electrospray ionization hybrid quadrupole time-of-flight (ESI-Q-TOF) MS. The retention time and accurate mass for each N-glycan were recorded in the library. The complete structures were obtained through exoglycosidase sequencing. The results showed that most of the N-glycans between different antibodies are nearly the same with different abundances. The utility of this library enables one to identify structures in a rapid manner by matching LC retention times and accurate masses

Correction to 3‑Thiomorpholin-8-oxo‑8<i>H</i>‑acenaphtho[1,2‑<i>b</i>]pyrrole-9-carbonitrile (S1) Based Molecules as Potent, Dual Inhibitors of B‑Cell Lymphoma 2 (Bcl-2) and Myeloid Cell Leukemia Sequence 1 (Mcl-1): Structure-Based Design and Structure–Activity Relationship Studies

Correction to 3‑Thiomorpholin-8-oxo‑8<i>H</i>‑acenaphtho[1,2‑<i>b</i>]pyrrole-9-carbonitrile (S1) Based Molecules as Potent, Dual Inhibitors of B‑Cell Lymphoma 2 (Bcl-2) and Myeloid Cell Leukemia Sequence 1 (Mcl-1): Structure-Based Design and Structure–Activity Relationship Studie

Gas-Exfoliation Assisted Fabrication of Porous Graphene Nanosheets Derived from <i>Plumeria rubra</i> for Highly Efficient Photocatalytic Hydrogen Evolution

An environmentally friendly strategy was performed to prepare porous graphene nanosheets (PGS) through gas-exfoliation assisted KOH activation by using Plumeria rubra as the precursor for the first time. Because the synergistic reaction of various graphitization temperature and activating agent amounts, the precursor was gradually exfoliated by released gases, graphitizing at high temperatures and forming porous graphene nanosheets during the graphitization. PGS-2-1000 with a hierarchical porous structure possessed high graphitization (<i>I</i>_D/<i>I</i>_G = 0.77, <i>I</i>_2D/<i>I</i>_G = 0.53), ultrahigh specific surface (1581 m² g^–1) and large pore volume (0.916 cm³ g^–1). A facile <i>in situ</i> photoreduction treatment was utilized to form a Cu/PGS photocatalyst composed of nonsemiconductor plasmonic Cu NPs and porous graphene nanosheets, exhibiting the hydrogen evolution rate of 4.87 mmol g^–1 h^–1, which is 4-fold as high as that of single Cu NPs. The photostability of Cu/PGS-2-1000 was investigated in five consecutive runs of 30 h accumulative irradiation. The PGS could act as an electron transport bridge to boost the separation of electron–hole pairs and the uniform distribution of Cu NPs, even serve as a photocatalyst for hydrogen generation. Furthermore, a possible mechanism was proposed to illustrate the circumstantial charge transfer channel as well as the improvement of photocatalytic activity

Quantitation of Site-Specific Glycosylation in Manufactured Recombinant Monoclonal Antibody Drugs

During the development of recombinant monoclonal antibody (rMAb) drugs, glycosylation receives particular focus because changes in the attached glycans can have a significant impact on the antibody effector functions. The vast heterogeneity of structures that exist across glycosylation sites hinders the in-depth analysis of glycan changes specific to an individual protein within a complex mixture. In this study, we established a sensitive and specific method for monitoring site-specific glycosylation in rMAbs using multiple reaction monitoring (MRM) on an ultrahigh-performance liquid chromatography–triple quadrupole MS (UHPLC-QqQ-MS). Our results showed that irrespective of the IgG subclass expressed in the drugs, the N-glycopeptide profiles are nearly the same but differ in abundances. In all rMAb drugs, a single subclass of IgG comprised over 97% of the total IgG content and showed over 97% N-glycan site occupancy. This study demonstrates the utility of an MRM-based method to rapidly characterize over 130 distinct glycopeptides and determine the extent of site occupancy within minutes. Such multilevel structural characterization is important for the successful development of therapeutic antibodies

Workflow for the IMRT TPS-QC tool.

<p>Workflow for the IMRT TPS-QC tool.</p

Dosimetric endpoints and criteria for assessing IMRT plan quality.

<p>Dosimetric endpoints and criteria for assessing IMRT plan quality.</p

Bcl-2/MDM2 Dual Inhibitors Based on Universal Pyramid-Like α‑Helical Mimetics

No α-helical mimetic that exhibits Bcl-2/MDM2 dual inhibition has been rationally designed due to the different helicities of the α-helixes at their binding interfaces. Herein, we extracted a one-turn α-helix-mimicking <i>ortho</i>-triarene unit from <i>o</i>-phenylene foldamers. Linking benzamide substrates with a rotatable C–N bond, we constructed a novel semirigid pyramid-like scaffold that could support its two-turn α-helix mimicry without aromatic stacking interactions and could adopt the different dihedral angles of the key residues of p53 and BH3-only peptides. On the basis of this universal scaffold, a series of substituent groups were installed to capture the key residues of both p53TAD and BimBH3 and balance the differences of the bulks between them. Identified by FP, ITC, and NMR spectroscopy, a compound <b>6e</b> (<b>zq</b>-<b>1</b>) that directly binds to Mcl-1, Bcl-2, and MDM2 with balanced submicromolar affinities was obtained. Cell-based experiments demonstrated its antitumor ability through Bcl-2/MDM2 dual inhibition simultaneously

A QC report example for one clinically approved cervical cancer IMRT plan.

<p>A QC report example for one clinically approved cervical cancer IMRT plan.</p