Short but promising - how nature modulates the antimicrobial activity of proline-rich fragment of salivary MUC-7.

Antimicrobial peptides (AMPs), including mucin-derived sequences, play a vital role in host defense at mucosal surfaces by modulating microbial interactions and supporting innate immunity. However, their susceptibility to proteolytic cleavage limits their protective efficacy. This study investigates the peptide FPNPHQPPKHPDK (L1), derived from human salivary mucin MUC7, and its proteolytic fragments L2 (FPNPHQPPK) and L3 (HPDK), generated by trypsin cleavage.

Exploring zinc(II) ion binding and antimicrobial activity D-amino acid substitution and modifications in MUC7 peptide from human saliva.

Antimicrobial peptides are part of the host's innate immune response and have high therapeutic potential, especially in the complexes with Zn(II) ions. However, this potential is limited by poor proteolytic stability. To prevent this, their peptidomimetic modifications, such as D-amino acid substitution or strategy, are a worthy alternative.

Modulating Copper(II) Coordination and Antimicrobial Activity: Effects of d-Amino Acid Substitution and Modification in Human Saliva MUC7 Peptide.

Fragments of MUC7, a salivary protein involved in nonimmune defense, arise from proteolytic cleavage in saliva and exhibit antimicrobial properties. However, their therapeutic use is limited by low stability due to further degradation. To address this, a native MUC7 fragment was modified using d-amino acids and the strategy.

A multi-technique approach to enlighten the role of metal coordination in calcitermin antiviral properties.

In this work we presented how the use of suitable electroanalytical, thermodynamic and spectroscopic methods combined with proper experimental conditions can provide comprehensive information on the interaction between metal ions and peptides in solution, as a successful strategy for studying biological systems. Our candidate peptide is calcitermin, an effective metal chelator with significant anti-Candida and antibacterial activity in the presence of divalent metals. While the bioinorganic chemistry of calcitermin with zinc and copper is quite well described in the literature, no data about nickel complexes are available; we therefore deepened calcitermin ability to form nickel complexes by different analytical techniques, including potentiometry, ultraviolet-visible absorption spectrophotometry, circular dichroism and high-resolution mass spectrometry.

Bioinorganic Chemistry Meets Microbiology: Copper(II) and Zinc(II) Complexes Doing the Cha-Cha with the C-t-CCL-28 Peptide, Dancing till the End of Microbes.

The necessity to move away from conventional antibiotic therapy has sparked interest in antimicrobial peptides (AMPs). One fascinating example is human CCL-28 chemokine produced by acinar epithelial cells in the salivary glands. It can also be released into the oral cavity with saliva, playing a crucial role in oral protection.

Insights into the Chemistry, Structure, and Biological Activity of Human Salivary MUC7 Fragments and Their Cu(II) and Zn(II) Complexes.

Mucin 7 (MUC7) is one of the salivary proteins whose role in the innate immune system is widely known, but still, neither its mechanism of action nor the impact of its metal coordination is fully understood. MUC7 and its fragments demonstrate potent antimicrobial activity, serving as a natural defense mechanism for organisms against pathogens. This study delves into the bioinorganic chemistry of MUC7 fragments (L1─EGRERDHELRHRRHHHQSPK; L2─EGRERDHELRHRR; L3─HHHQSPK) and their complexes with Cu(II) and Zn(II) ions.

Bioinorganic chemistry of shepherin II complexes helps to fight Candida albicans?

The fungal cell wall and cell membrane are an important target for antifungal therapies, and a needle-like cell wall or membrane disruption may be an entirely novel antifungal mode of action. In this work, we show how the coordination of Zn(II) triggers the antifungal properties of shepherin II, a glycine- and histidine-rich antimicrobial peptide from the root of Capsella bursa-pastoris. We analyze Cu(II) and Zn(II) complexes of this peptide using experimental and theoretical methods, such as: mass spectrometry, potentiometry, UV-Vis and CD spectroscopies, AFM imaging, biological activity tests and DFT calculations in order to understand the correlation between their metal binding mode, structure, morphology and biological activity.

Zn(II) Induces Fibril Formation and Antifungal Activity in Shepherin I, An Antimicrobial Peptide from .

Shepherin I is a glycine- and histidine-rich antimicrobial peptide from the root of a shepherd's purse, whose antimicrobial activity was suggested to be enhanced by the presence of Zn(II) ions. We describe Zn(II) and Cu(II) complexes of this peptide, aiming to understand the correlation between their metal binding mode, structure, morphology, and biological activity. We observe a logical sequence of phenomena, each of which is the result of the previous one: (i) Zn(II) coordinates to shepherin I, (ii) causes a structural change, which, in turn, (iii) results in fibril formation.