scholarly journals The Fungal Defensin Family Enlarged

2014 ◽  
Vol 7 (8) ◽  
pp. 866-880 ◽  
Author(s):  
Jiajia Wu ◽  
Bin Gao ◽  
Shunyi Zhu
Keyword(s):  
Fungal Defensin

scholarly journals A Fungal Defensin Targets the SARS−CoV−2 Spike Receptor−Binding Domain

2021 ◽  
Vol 7 (7) ◽  
pp. 553
Author(s):  
Bin Gao ◽  
Shunyi Zhu
Keyword(s):  
Receptor Binding ◽  
Viral Entry ◽  
Single Point ◽  
Binding Domain ◽  
Host Cells ◽  
Single Point Mutation ◽  
Binding Motif ◽  
Microsporum Canis ◽  
Receptor Binding Domain ◽  
Fungal Defensin

Coronavirus Disease 2019 (COVID−19) elicited by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS−CoV−2) is calling for novel targeted drugs. Since the viral entry into host cells depends on specific interactions between the receptor−binding domain (RBD) of the viral Spike protein and the membrane−bound monocarboxypeptidase angiotensin converting enzyme 2 (ACE2), the development of high affinity RBD binders to compete with human ACE2 represents a promising strategy for the design of therapeutics to prevent viral entry. Here, we report the discovery of such a binder and its improvement via a combination of computational and experimental approaches. The binder micasin, a known fungal defensin from the dermatophytic fungus Microsporum canis with antibacterial activity, can dock to the crevice formed by the receptor−binding motif (RBM) of RBD via an extensive shape complementarity interface (855.9 Å2 in area) with numerous hydrophobic and hydrogen−bonding interactions. Using microscale thermophoresis (MST) technique, we confirmed that micasin and its C−terminal γ−core derivative with multiple predicted interacting residues exhibited a low micromolar affinity to RBD. Expanding the interface area of micasin through a single point mutation to 970.5 Å2 accompanying an enhanced hydrogen bond network significantly improved its binding affinity by six−fold. Our work highlights the naturally occurring fungal defensins as an emerging resource that may be suitable for the development into antiviral agents for COVID−19.

scholarly journals Oxidative stress and the presence of bacteria increase gene expression of the antimicrobial peptide aclasin, a fungal CSαβ defensin in Aspergillus clavatus

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6290 ◽  
Author(s):  
Gabriela Contreras ◽  
Nessa Wang ◽  
Holger Schäfer ◽  
Michael Wink
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Heat Shock ◽  
Osmotic Stress ◽  
Broad Class ◽  
Stress Conditions ◽  
Aspergillus Clavatus ◽  
Stress Oxidative ◽  
Fungal Defensin ◽  
Β Sheet

Background Antimicrobial peptides (AMPs) represent a broad class of naturally occurring antimicrobial compounds. Plants, invertebrates and fungi produce various AMPs as, for example, defensins. Most of these defensins are characterised by the presence of a cysteine-stabilised α-helical and β-sheet (CSαβ) motif. The changes in gene expression of a fungal CSαβ defensin by stress conditions were investigated in Aspergillus clavatus. A. clavatus produces the CSαβ defensin Aclasin, which is encoded by the aclasin gene. Methods Aclasin expression was evaluated in submerged mycelium cultures under heat shock, osmotic stress, oxidative stress and the presence of bacteria by quantitative real-time PCR. Results Aclasin expression increased two fold under oxidative stress conditions and in the presence of viable and heat-killed Bacillus megaterium. Under heat shock and osmotic stress, aclasin expression decreased. Discussion The results suggest that oxidative stress and the presence of bacteria might regulate fungal defensin expression. Moreover, fungi might recognise microorganisms as plants and animals do.

scholarly journals Eurocin, a New Fungal Defensin

2012 ◽  
Vol 287 (50) ◽  
pp. 42361-42372 ◽  
Author(s):  
Jesper S. Oeemig ◽  
Carina Lynggaard ◽  
Daniel H. Knudsen ◽  
Frederik T. Hansen ◽  
Kent D. Nørgaard ◽  
...  
Keyword(s):  
Fungal Defensin

A recombinant fungal defensin-like peptide-P2 combats Streptococcus dysgalactiae and biofilms

2021 ◽  
Vol 105 (4) ◽  
pp. 1489-1504
Author(s):  
Qingjuan Zhang ◽  
Na Yang ◽  
Ruoyu Mao ◽  
Ya Hao ◽  
Xuanxuan Ma ◽  
...  
Keyword(s):  
Streptococcus Dysgalactiae ◽  
Fungal Defensin

The second N-terminal aromatic residue of the fungal defensin, blapersin, of Blastomyces percursus is essential for its antibacterial activity

Peptides ◽  
2020 ◽  
Vol 133 ◽  
pp. 170400
Author(s):  
Jiajia Wu ◽  
Chao Qu ◽  
Shunliang Zhang ◽  
Wenhua Chen ◽  
Shouwei Wang
Keyword(s):  
Antibacterial Activity ◽  
Aromatic Residue ◽  
Fungal Defensin

scholarly journals Plectasin, First Animal Toxin-Like Fungal Defensin Blocking Potassium Channels through Recognizing Channel Pore Region

Toxins ◽  
2015 ◽  
Vol 7 (1) ◽  
pp. 34-42 ◽  
Author(s):  
Fang Xiang ◽  
Zili Xie ◽  
Jing Feng ◽  
Weishan Yang ◽  
Zhijian Cao ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Pore Region ◽  
Channel Pore ◽  
Fungal Defensin

scholarly journals New fungal defensin-like peptides provide evidence for fold change of proteins in evolution

2017 ◽  
Vol 37 (1) ◽  
Author(s):  
Yucheng Wu ◽  
Bin Gao ◽  
Shunyi Zhu
Keyword(s):  
Disulfide Bridge ◽  
Fold Change ◽  
Structure Conservation ◽  
Fold Formation ◽  
Fungal Defensin ◽  
Α Helix ◽  
Residue Numbers ◽  
Evolution Of Proteins ◽  
Multicellular Organisms ◽  
Β Sheet

Defensins containing a consensus cystine framework, Cys[1]…Cys[2]X3Cys[3]…Cys[4]… Cys[5]X1Cys[6] (X, any amino acid except Cys; …, variable residue numbers), are extensively distributed in a variety of multicellular organisms (plants, fungi and invertebrates) and essentially involved in immunity as microbicidal agents. This framework is a prerequisite for forming the cysteine-stabilized α-helix and β-sheet (CSαβ) fold, in which the two invariant motifs, Cys[2]X3Cys[3]/Cys[5]X1Cys[6], are key determinants of fold formation. By using a computational genomics approach, we identified a large superfamily of fungal defensin-like peptides (fDLPs) in the phytopathogenic fungal genus – Zymoseptoria, which includes 132 structurally typical and 63 atypical members. These atypical fDLPs exhibit an altered cystine framework and accompanying fold change associated with their secondary structure elements and disulfide bridge patterns, as identified by protein structure modelling. Despite this, they definitely are homologous with the typical fDLPs in view of their precise gene structure conservation and identical precursor organization. Sequence and structural analyses combined with functional data suggest that most of Zymoseptoria fDLPs might have lost their antimicrobial activity. The present study provides a clear example of fold change in the evolution of proteins and is valuable in establishing remote homology among peptide superfamily members with different folds.

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