The formation of a cell wall is vital for the survival and growth of a fungal cell. Fungi express members of the GH76 family of α-1,6-mannanases which play an important role in cell wall biogenesis. In this report we characterize the Neurospora crassa DFG-5 α-1,6-mannanase and demonstrate that it binds to the α-1,6-mannose backbone of an N-linked galactomannan found on cell wall glycoproteins. We show that DFG-5 has an enzymatic activity and provide evidence that it processes the α-1,6-mannose backbone of the N-linked galactomannan. Site-directed mutagenesis and complementation experiments show that D116 and D117 are located at the DFG-5 active site. D76 and E130, which are located in a groove on the opposite side of the protein, are also important for enzyme function. Cell wall glycoproteins co-purify with DFG-5 demonstrating a specific association between DFG-5 and cell wall glycoproteins. DFG-5 is able to discriminate between cell wall and secreted glycoproteins, and does not bind to the N-linked galactomannans present on secreted glycoproteins. DFG-5 plays a key role in targeting extracellular glycoproteins to their final destinations. By processing the galactomannans on cell wall proteins, DFG-5 targets them for cell wall incorporation by lichenin transferases. The N-linked galactomannans on secreted proteins are not processed by DFG-5, which targets these proteins for release into the extracellular medium.

2022-04-01·BMJ Open4区 · 医学

Responsiveness of the HUG-5 in an outpatient clinic: a 12-month randomised feasibility study protocol

4区 · 医学

ArticleOA

作者: Chan, Brian ; Nanji, Keean ; Chan, Jenny ; Sogbesan, Enitan ; Hatamnejad, Amin ; Xie, Feng ; Wu, Michael ; Patil, Nikhil ; Kennedy, Kevin ; Xie, Jim

IntroductionGlaucoma is a progressive, chronic condition that can have a significant impact on a patient’s health-related quality of life (HRQoL). Validated, disease-specific HRQoL tools such as the Health Utility for Glaucoma (HUG-5) tool and the Glaucoma Quality of Life Questionnaire (GlauQoL-17) can be used to monitor a patient’s quality of life. However, the utility of these tools in outpatient clinic practice is not well established. The primary objective of this study is to characterise the feasibility of administering periodic HRQoL questionnaires in glaucoma using a semi-automated workflow.Methods and analysisThis study will be a single-centre, unblinded, randomised, parallel-group study with an exploratory data analysis framework. We aim to determine the feasibility of administering the HUG-5 in an outpatient clinic using a semi-automated workflow and determine patient engagement through email and telephone contact methods. We will also be investigating the association of the HUG-5 and GlauQoL-17 with patient visual field testing and visual acuity. Mean differences between groups will be tested with analysis of variance to determine if the frequency of calls affects burden, satisfaction and perceived value of information.Ethics and disseminationThis study has been approved by the Hamilton Integrated Research Ethics board (ID: 13046) and will be conducted within Canadian Tri-Council Statement policy. Personal information of the study’s participants will be anonymised with identification codes and data will be kept on an encrypted server. Results of this study will be disseminated through peer-reviewed journals, conferences and internal meetings.

2022-03-14·Biomacromolecules2区 · 化学

Polyanionic Amphiphilic Dendritic Polyglycerols as Broad-Spectrum Viral Inhibitors with a Virucidal Mechanism

2区 · 化学

Article

作者: Achazi, Katharina ; Tapparel, Caroline ; Mohammadifar, Ehsan ; Haag, Rainer ; Gasbarri, Matteo ; Stellacci, Francesco ; Cagno, Valeria

Heparin has been known to be a broad-spectrum inhibitor of viral infection for almost 70 years, and it has been used as a medication for almost 90 years due to its anticoagulant effect. This nontoxic biocompatible polymer efficiently binds to many types of viruses and prevents their attachment to cell membranes. However, the anticoagulant properties are limiting their use as an antiviral drug. Many heparin-like compounds have been developed throughout the years; however, the reversible nature of the virus inhibition mechanism has prevented their translation to the clinics. In vivo, such a mechanism requires the unrealistic maintenance of the concentration above the binding constant. Recently, we have shown that the addition of long hydrophobic linkers to heparin-like compounds renders the interaction irreversible while maintaining the low-toxicity and broad-spectrum activity. To date, such hydrophobic linkers have been used to create heparin-like gold nanoparticles and β-cyclodextrins. The former achieves a nanomolar inhibition concentration on a non-biodegradable scaffold. The latter, on a fully biodegradable scaffold, shows only a micromolar inhibition concentration. Here, we report that the addition of hydrophobic linkers to a new type of multifunctional scaffold (dendritic polyglycerol, dPG) creates biocompatible compounds endowed with nanomolar activity. Furthermore, we present an in-depth analysis of the molecular design rules needed to achieve irreversible virus inhibition. The most active compound (dPG-5) showed nanomolar activity against herpes simplex virus 2 (HSV-2) and respiratory syncytial virus (RSV), giving a proof-of-principle for broad-spectrum while keeping low-toxicity. In addition, we demonstrate that the virucidal activity leads to the release of viral DNA upon the interaction between the virus and our polyanionic dendritic polymers. We believe that this paper will be a stepping stone toward the design of a new class of irreversible nontoxic broad-spectrum antivirals.

100 项与 rhGDG-5 相关的药物交易

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