In this research, the characteristic ions' abundance ratio between two isomers A and B in MS/MS mass spectra was defined as a parameter for discriminating diastereomers. Through this ratio, the discrimination of four pairs of cyclic peptide (CP) diastereomers was successfully achieved. Furthermore, in the analysis of diastereomers' mixtures, both calibration curve and calculational methods were substantiated to have high precision and accuracy. The average absolute errors of the two methods were 2.0 and 2.5% in the 48 measurements of 16 samples, respectively. This research provided a promising approach for the analysis of the CP diastereomers in the fields of asymmetrical synthesis, chiral natural products and structural biology by ESI-MS/MS.
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http://dx.doi.org/10.1002/jms.1635 | DOI Listing |
Sci Adv
January 2025
Department of Rheumatology and Immunology, Peking University People's Hospital & Beijing Key Laboratory for Rheumatism Mechanism and Immune Diagnosis (BZ0135), Beijing, China.
Current diagnosis and treatment of rheumatoid arthritis (RA) is still challenging. More than one-third of patients with RA could not be accurately diagnosed because of lacking biomarkers. Our recent study reported that scavenger receptor-A (SR-A) is a biomarker for RA, especially for anticyclic citrullinated peptide antibody (anti-CCP)-negative RA.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Shenzhen Bay Laboratory, Shenzhen, Guandong, China.
Background: The classic mode of STING activation is through binding the cyclic dinucleotide 2'3'-cyclic GMP-AMP (cGAMP), produced by the DNA sensor cyclic GMP-AMP synthase (cGAS), which is important for the innate immune response to microbial infection and autoimmune disease. Modes of STING activation that are independent of cGAS are much less well understood. We wanted to explore the interactome of STING on the organelles during its trafficking route and to understand the regulatory network of STING signaling.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Background: Clinicopathological studies of Alzheimer's disease (AD) have demonstrated that synaptic or neuronal loss and clinical cognitive decline do not reliably correlate with fibrillar amyloid burden. We created a transgenic mouse model overexpressing Dutch (E693Q) mutant human amyloid precursor protein (APP) driven by the pan-neuronal Thy1 promoter. Accumulation of APP carboxyl-terminal fragments was observed in the brains of these mice, which develop an impaired learning phenotype directly proportional to brain oAβ levels.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Biomedical Engineering, Graduate School of Medicine, Science and Technology, Shinshu University, Nagano, 390-8621, Japan.
Lysophosphatidylethanolamine (LPE) is a bioactive lipid mediator involved in diverse cellular functions. In this study, we investigated the effects of three LPE species, 1-palmitoyl LPE (16:0 LPE), 1-stearoyl LPE (18:0 LPE), and 1-oleoyl LPE (18:1 LPE) on pre-osteoblast MC3T3-E1 cells. All LPE species stimulated cell proliferation and activated the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) 1/2.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
January 2025
Department of Ophthalmology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Purpose: This study aimed to identify a novel recombinant adeno-associated virus (rAAV) capsid variant that can widely transfect the deep retina through intravitreal injection and to assess their effectiveness and safety in gene delivery.
Methods: By adopting the sequences of various cell-penetrating peptides and inserting them into the capsid modification region of AAV2, we generated several novel variants. The green fluorescent protein (GFP)-carrying variants were screened following intravitreal injection.
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