CN-121971426-A - Application of nitrosylation modification of MgrA protein in treatment of staphylococcus aureus biofilm infection

Abstract

The invention relates to the technical field of microbial infection treatment and molecular biology, and provides a method for inhibiting formation of a biological film of staphylococcus aureus, which is realized by inhibiting nitrosylation modification of MgrA protein in staphylococcus aureus so as to inhibit formation of the biological film, wherein the inhibitor is nitric oxide synthase so as to inhibit nitrosylation modification of MgrA protein, nitrosylation modification of MgrA protein is realized by applying a Nitric Oxide Synthase (NOS) inhibitor, the invention reveals for the first time that endogenous nitric oxide of staphylococcus aureus can promote formation of the biological film by modifying the 12 th cysteine of regulatory protein MgrA, and based on the target point, researches prove that the gene mutation, the NOS inhibitor or combination of the NOS inhibitor and antibiotics can effectively reduce MgrA modification level and enhance removal of the biological film, thereby providing a new strategy and potential drug development approach for preventing and treating refractory biological film infection of staphylococcus aureus.

Inventors

• HUANG YI
• SHU XUEQIN
• SUN BAOLIN

Assignees

• 安徽中科生命科学技术有限公司

Dates

Publication Date

20260505

Application Date

20260209

Claims (9)

1. 1. A method for inhibiting formation of a biofilm of staphylococcus aureus is characterized by inhibiting nitrosylation modification of MgrA protein in staphylococcus aureus, and further inhibiting formation of the biofilm, wherein the inhibitor is nitric oxide synthase, so that nitrosylation modification of MgrA protein is inhibited.
2. 2. The method of inhibiting biofilm formation by Staphylococcus aureus according to claim 1, wherein the nitric oxide synthase inhibitor is L-NAME.
3. 3. The method of inhibiting the formation of a biofilm of Staphylococcus aureus according to claim 1, wherein said nitrosylation modification of the MgrA protein is performed by modifying or mutating the cysteine (C12) at position 12 of the MgrA protein to an amino acid free of thiol groups.
4. 4. The method of inhibiting the formation of a biofilm of Staphylococcus aureus according to claim 3, wherein said thiol-free amino acid is serine, i.e., mgrA-C12S mutant is constructed.
5. 5. A pharmaceutical composition for preventing or treating a staphylococcus aureus biofilm infection, comprising a Nitric Oxide Synthase (NOS) inhibitor and/or a MgrA protein nitrosylation modification inhibitor, and a pharmaceutically acceptable carrier.
6. 6. The pharmaceutical composition for preventing or treating a Staphylococcus aureus biofilm infection as set forth in claim 5, further comprising at least one antibiotic for resisting Staphylococcus aureus infection.
7. 7. The pharmaceutical composition for preventing or treating a Staphylococcus aureus biofilm infection according to claim 6, wherein the antibiotic is one or more selected from vancomycin, daptomycin, and linezolid.
8. Nitrosylation modification of cysteine (C12) at 12 th position of MgrA protein as target spot, and application in screening or preparing medicine for inhibiting formation of staphylococcus aureus biofilm.
9. 9. A kit for treating a staphylococcus aureus biofilm infection, comprising a Nitric Oxide Synthase (NOS) inhibitor.

Description

Application of nitrosylation modification of MgrA protein in treatment of staphylococcus aureus biofilm infection Technical Field The invention relates to the technical fields of microbial infection treatment and molecular biology, in particular to application of nitrosylation modification of MgrA protein in treatment of staphylococcus aureus biofilm infection. Background Staphylococcus aureus is an important human pathogen, which can cause a variety of infections. Its ability to form biofilms is a central cause of chronic, recurrent, and implant-related infections that are difficult to cure. The biological envelope is a structural community formed by wrapping the bacteria on the surface by an extracellular matrix secreted by the bacteria, so that the tolerance to antibiotics and immune escape can be remarkably enhanced; The current clinical approaches to such infections are limited, mainly relying on surgical debridement, implant removal and long-term large-dose antibiotics, with insufficient efficacy and heavy burden. Therefore, there is an urgent need to find key targets for controlling the biofilm and develop new strategies; The gas signal molecule Nitric Oxide (NO) has important regulation and control functions in both prokaryotes and eukaryotes. Staphylococcus aureus possesses bacterial Nitric Oxide Synthase (NOS), which can endogenously synthesize NO and modify protein cysteine residues by nitrosylation, affecting its function. The prior art (such as CN 114088946B) reveals that endogenous NO regulates vancomycin resistance through modification WalR and MgrA, but whether and how to regulate biofilm formation are not reported, and the potential of the endogenous NO as a biofilm treatment target point is not explored. Disclosure of Invention The invention provides application of MgrA protein nitrosylation modification serving as a target point in preparation of a medicament, a kit or a treatment method for inhibiting staphylococcus aureus biofilm formation and preventing and/or treating staphylococcus aureus biofilm related infection. The aim of the invention can be achieved by the following technical scheme that the method for inhibiting the formation of the biological film of staphylococcus aureus is achieved by inhibiting the nitrosylation modification of MgrA protein in staphylococcus aureus, so as to inhibit the formation of the biological film, wherein the inhibitor is nitric oxide synthase, so as to inhibit the nitrosylation modification of MgrA protein. Preferably, the nitrosylation modification of the MgrA-inhibiting protein is achieved by administration of a Nitric Oxide Synthase (NOS) inhibitor. Preferably, the NOS inhibitor is L-NAME or a pharmaceutically acceptable salt thereof. Preferably, the nitrosylation modification of the MgrA-inhibiting protein is achieved by modifying or mutating the cysteine (C12) at position 12 of the MgrA protein to a thiol-free amino acid. Preferably, the thiol-free amino acid is serine, i.e., a MgrA-C12S mutant is constructed. The invention also provides a pharmaceutical composition for preventing or treating staphylococcus aureus biofilm infection, which comprises a Nitric Oxide Synthase (NOS) inhibitor and/or MgrA protein nitrosylation modification inhibitor and a pharmaceutically acceptable carrier. Preferably, at least one antibiotic for combating staphylococcus aureus infections is also included. Preferably, the antibiotic is selected from one or more of vancomycin, daptomycin and linezolid. The invention also provides application of the nitrosylation modification of the MgrA th cysteine (C12) of the MgrA th protein as a target spot in screening or preparing medicines for inhibiting formation of staphylococcus aureus biofilm. The invention also provides a kit for treating staphylococcus aureus biofilm infection, which comprises a Nitric Oxide Synthase (NOS) inhibitor. The invention has the beneficial effects that: The invention determines that the endogenous NO of staphylococcus aureus is modified by nitrosylation of NOS-mediated transcription factor MgrA (C12) at position 12 so as to positively regulate and control biofilm formation for the first time, and the determination not only clarifies a molecular path of low-concentration NO for promoting biofilm formation, but also establishes the nitrosylation state of MgrA as a brand-new and well-defined anti-biofilm treatment target point; Based on the target, research proves that multilevel intervention means including gene point mutation (MgrA-C12S), NOS inhibitors (such as L-NAME) and combination of the inhibitors and antibiotics (such as vancomycin) can effectively reduce MgrA nitrosation level and synergistically enhance clearance of formed biological films, and provides multiple approaches from upstream inhibition to downstream blocking for drug development; The achievement has clear clinical transformation prospect, for example, the NOS inhibitor is used for implant coating or local administration to pr