Polypeptide of targeted elastic fiber, probe and application of polypeptide

Abstract

The invention discloses a polypeptide targeting an elastic fiber, a probe and application of the polypeptide, the amino acid sequence of the polypeptide is YGQVPMCDAGEQCAVRKGARI, and the polypeptide can specifically recognize the elastic fiber, has good biocompatibility and can be used as a tool for in-vivo imaging, drug delivery, function regulation and control and the like. The sequences of human and rodents are consistent, so that the method can be directly applied to a rodent model to carry out basic research and preclinical research related to the elastic fibers.

Description

Technical Field

[0001] This invention belongs to the field of medical cell biology, and in particular relates to a polypeptide, probe and its application targeting elastic fibers. Background Technology

[0002] Elastic fibers are essential components of connective tissue, widely distributed in tissues such as skin, lungs, and blood vessels, giving these tissues their elasticity. These fibers are mainly composed of elastin and microfibers, and their conformational stability and biological activity are crucial for normal tissue function. However, under various pathological conditions such as aging, ultraviolet radiation, and persistent inflammation, these elastic fibers often become damaged, decomposed, or abnormally remodeled, significantly weakening tissue elasticity and subsequently leading to functional abnormalities. Precise localization, detection, or intervention in the identification of elastic fibers has not only fundamental research value but also significant medical diagnostic and therapeutic value. Existing methods for identifying elastic fibers mainly include elastic fiber dye staining and antibody labeling, which can be used for imaging elastic fibers in tissue sections, but these methods suffer from poor penetration, limited specificity, or inapplicability to in vivo imaging. Chinese patent application No. 202310408541.7 discloses a "novel probe for targeting and binding elastin and its biomedical application". The probe is a fluorescent probe based on glycopeptide antibiotics or lipoglycopeptide antibiotics, mainly including fluorescent probes prepared based on vancomycin, teicoplanin, tervacin, etc. The antibiotic components are microbial metabolites, and their application in living organisms will cause side effects such as kidney damage and allergies. Clinical application needs to be strictly controlled.

[0003] Targeted peptides can precisely locate specific molecules by specifically recognizing and binding to target cells / molecules, offering advantages such as high specificity and ease of modification. Their mechanism of action is as follows: 1) Direct regulation: It can act as an active molecule to directly inhibit / activate signaling pathways by binding to targets; 2) Molecular markers: After being combined with fluorescent groups, radionuclides, etc., probes are made to specifically identify diseased tissue cells, so as to achieve early and accurate diagnosis of diseases, such as imaging detection and pathological biopsy.

[0004] 3) Drug delivery: By loading drugs, they are precisely delivered to the lesion site, reducing damage to normal cells and lowering the toxic side effects of drugs on the body; However, to date, there have been no reports on peptides, probes, or applications that specifically target elastic fibers. Summary of the Invention

[0005] The present invention addresses the aforementioned technical problems in the prior art by providing a polypeptide, probe, and its application targeting elastic fibers.

[0006] The technical solution of the present invention is a polypeptide that targets elastic fibers, the amino acid sequence of which is YGQVPMCDAGEQCAVRKGARI.

[0007] A probe targeting elastic fibers is a probe prepared from the aforementioned peptides targeting elastic fibers.

[0008] Preferred probes are fluorescent probes, radioactive probes, or magnetic resonance imaging probes.

[0009] The preferred probe is a fluorescent probe formed by coupling a peptide targeting elastic fibers with a Cy5 fluorescent dye.

[0010] The preferred probe is a peptide targeting elastic fibers coupled with a Cy5 fluorescent dye via a click chemistry reaction.

[0011] The application of the above-mentioned probe for targeting elastic fibers in in vivo or in vitro localization, imaging or detection of elastic fibers.

[0012] Application of the aforementioned peptide targeting elastic fibers in basic research, disease diagnosis, targeted drug delivery, or functional regulation related to elastic fibers.

[0013] The peptide targeting elastic fibers provided by this invention can specifically recognize elastic fibers and has good biocompatibility, making it a tool for in vivo imaging, drug delivery, and functional regulation. Since the sequence is identical in humans and rodents, it can be directly applied to rodent models for basic and preclinical research related to elastic fibers. Attached Figure Description

[0014] Figure 1 This is a detection diagram of targeted signals of elastic fibers in mouse skin in an embodiment of the present invention. Detailed Implementation

[0015] Example 1: Screening and preparation of peptides targeting elastic fibers The polypeptide targeting elastic fibers of the present invention has the amino acid sequence YGQVPMCDAGEQCAVRKGARI, which is a polypeptide (natural sequence) targeting elastic fibers obtained based on screening of the human CARTPT gene. The peptides targeting elastic fibers of this invention can be prepared using conventional methods in this technical field, such as chemical synthesis methods (e.g., solid-phase synthesis) and biosynthesis methods (e.g., gene engineering expression synthesis). In this embodiment, the amino acid sequence shown above was prepared using a solid-phase synthesis method. The synthesis process starts from the carboxyl terminus of the peptide and extends sequentially to the amino terminus. Through resin activation, amino acid incorporation, deprotection, and process monitoring, the linkage of each amino acid is completed sequentially. Subsequently, excess anhydrous diethyl ether is added to precipitate the product, which is then collected by centrifugation. The obtained primary peptide is further purified by HPLC, and finally, the sample is identified by mass spectrometry and rapidly lyophilized using liquid nitrogen for subsequent use.

[0016] Example 2: Preparation of peptide probes targeting elastic fibers The peptide targeting elastic fibers prepared in Example 1 of this invention was combined with Cy5 fluorescent dye via a click chemistry reaction.

[0017] Experiment: In vivo targeting of the peptides of this invention to mouse skin elastic fibers. 1) Laboratory mice: SPF-grade C57 mice, 7 weeks old; 2) Model construction: After the above-mentioned experimental mice were acclimatized for one week, the prepared probe was injected into their tail vein to construct a mouse model of targeting elastic fibers.

[0018] 3) Experimental methods and results: Twenty-four hours after probe injection, skin tissue from mice was dehaired, frozen sections were prepared, and cell nuclei were counterstained with DAPI before microscopic observation. The results are as follows: Figure 1 As shown. Figure 1 The red fluorescence signal is the probe fluorescence signal, consistent with the distribution characteristics of elastic fibers in mouse skin tissue, while the blue fluorescence is the nuclear DAPI staining signal, clearly showing the cellular structure background of the skin tissue. The results indicate that the targeting peptide probe of Example 2 of this invention can specifically recognize and bind to elastic fibers in mouse skin at the tissue level in vivo.

[0019] 4) Experimental Conclusions The targeting peptides of this invention can achieve precise targeting of elastic fibers in animals, providing experimental evidence of in vivo effectiveness for the subsequent development of diagnostic probes and targeted therapeutic drugs for functional disorders or diseases of elastic fibers-related tissues and organs, and proving the feasibility and advanced nature of the peptides of this invention in practical applications.

Claims

1. A polypeptide targeting elastic fibers, characterized in that... The amino acid sequence of the polypeptide is as follows: YGQVPMCDAGEQCAVRKGARI.

2. A probe for targeting elastic fibers, characterized in that... The probe is prepared from the peptide targeting elastic fibers as described in claim 1.

3. The probe for targeting elastic fibers according to claim 2, characterized in that... It is a fluorescent probe, a radioactive probe, or a magnetic resonance imaging probe.

4. The probe for targeting elastic fibers according to claim 3, characterized in that... It is a fluorescent probe formed by coupling a peptide targeting elastic fibers with a Cy5 fluorescent dye.

5. The probe for targeting elastic fibers according to claim 4, characterized in that: It involves coupling peptides targeting elastic fibers with Cy5 fluorescent dyes via a click chemistry reaction.

6. The application of a probe for targeting elastic fibers as described in claim 2, 3, 4 or 5 in the in vivo or in vitro localization, imaging or detection of elastic fibers.

7. The application of a polypeptide targeting elastic fibers as described in claim 1 in basic research, disease diagnosis, targeted drug delivery, or functional regulation related to elastic fibers.

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