Luz C. Mendez, Mitchell Kennedy, Surita R. Bhatia and Nicole S. Sampson*,
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引用次数: 0
Abstract
Carbohydrate recognition is imperative for the induction of sperm acrosomal exocytosis (AE), an essential phenomenon in mammalian fertilization. In mouse sperm, polynorbornene 100-mers displaying fucose or mannose moieties were effective at inducing AE. In contrast, glycopolymers exhibiting glucose sugars resulted in no AE activation. To further elucidate the role of ligand density on the activation of AE in mouse sperm, a triple-stain flow cytometry assay was employed to determine the efficacy of polynorbornene block copolymers with barbell-like sequences as initiators of AE. Triblock (ABA or ABC) copolymers were synthesized by ring-opening metathesis polymerization (ROMP) with one or two activating sugars, mannose or fucose, and one nonactivating sugar, glucose. The active ligand fractions in the polymers varied from 10, 20, or 40%. Simultaneously, random copolymers comprising 20% activating ligands were prepared to confirm the importance of ligand positionality in AE activation in mouse sperm. Polynorbornene 100-mers possessing two 10-mer blocks of activating sugars were the most effective copolymers at inducing AE with levels of AE comparable to their homopolymer counterparts and more effective than their random analogues. Small-angle X-ray scattering (SAXS) was then performed to verify that there were no differences in the conformations of the glycopolymers contributing to their varying AE activity. SAXS data analysis confirmed that all of the glycopolymers assumed semiflexible cylindrical structures with similar radii and Kuhn lengths. These findings suggest that the overall ligand density of the sugar moieties in the polymer is less important than the positionality of short blocks of high-density ligands for AE activation in mouse sperm.
期刊介绍:
ACS Bio & Med Chem Au is a broad scope open access journal which publishes short letters comprehensive articles reviews and perspectives in all aspects of biological and medicinal chemistry. Studies providing fundamental insights or describing novel syntheses as well as clinical or other applications-based work are welcomed.This broad scope includes experimental and theoretical studies on the chemical physical mechanistic and/or structural basis of biological or cell function in all domains of life. It encompasses the fields of chemical biology synthetic biology disease biology cell biology agriculture and food natural products research nucleic acid biology neuroscience structural biology and biophysics.The journal publishes studies that pertain to a broad range of medicinal chemistry including compound design and optimization biological evaluation molecular mechanistic understanding of drug delivery and drug delivery systems imaging agents and pharmacology and translational science of both small and large bioactive molecules. Novel computational cheminformatics and structural studies for the identification (or structure-activity relationship analysis) of bioactive molecules ligands and their targets are also welcome. The journal will consider computational studies applying established computational methods but only in combination with novel and original experimental data (e.g. in cases where new compounds have been designed and tested).Also included in the scope of the journal are articles relating to infectious diseases research on pathogens host-pathogen interactions therapeutics diagnostics vaccines drug-delivery systems and other biomedical technology development pertaining to infectious diseases.