CN-118344446-B - Polypeptide with binding affinity to AXL protein and application thereof

Abstract

The invention relates to the field of biological medicine and clinical diagnosis, in particular to a polypeptide with binding affinity to an AXL protein and application thereof, wherein the polypeptide has binding affinity to the AXL protein, so that the polypeptide can be used for detecting the AXL protein and has diagnostic or therapeutic application as a medicine or molecular targeting reagent.

Inventors

• ZHANG LIFANG
• CHEN JUN
• Du Wangqi
• ZHU SHANLI
• XUE XIANGYANG

Assignees

• 温州医科大学

Dates

Publication Date

20260508

Application Date

20240420

Claims (9)

1. 1. A polypeptide with binding affinity to AXL protein is characterized in that the polypeptide is obtained by taking an amino acid sequence of a Z segment of staphylococcal protein A as a skeleton and carrying out 14 amino acid mutation, and the amino acid sequence of the polypeptide is shown as SEQ ID NO. 3.
2. 2. A targeting molecule for targeting an AXL protein is characterized in that the targeting molecule consists of the polypeptide as set forth in claim 1 and a conjugate connected with the polypeptide, wherein the conjugate is a polypeptide tag or a detectable marker.
3. 3. A polynucleotide encoding the polypeptide of claim 1.
4. 4. A recombinant vector comprising the polynucleotide according to claim 3.
5. 5. A host cell, characterized in that: comprising the polynucleotide of claim 3.
6. 6. A host cell according to claim 5, wherein the polynucleotide according to claim 3 is integrated into the genome or the recombinant vector according to claim 4 is contained.
7. 7. Use of the polypeptide of claim 1 or the targeting molecule of claim 2 for detecting AXL protein for non-disease diagnostic, therapeutic purposes.
8. 8. Use of the polypeptide of claim 1 or the targeting molecule of claim 2 for the preparation of a detection reagent or kit for detecting AXL protein.
9. 9. The use of the polypeptide according to claim 1 or the targeting molecule according to claim 2 for the preparation of a pharmaceutical composition for the diagnosis or co-diagnosis of gastric cancer or nasopharyngeal carcinoma.

Description

Polypeptide with binding affinity to AXL protein and application thereof Technical Field The invention relates to the field of biological medicine and clinical diagnosis, in particular to a polypeptide with binding affinity to an AXL protein and application thereof. Background The AXL receptor (also known as UFO/ARK/Tyro7/JTK 11) is a member of the TAM family of Receptor Tyrosine Kinases (RTKs) and is widely expressed in a variety of cells and tissues in vivo. Together with Tyro3 (also called Sky/Rse) and merTK (also called Eyk/Nyk/Tyro 12), it forms a TAM receptor family, and plays an important role in cytoburial, immune balance, inflammatory reaction and the like. The AXL gene was located on human chromosome 19, q13.2, and was originally isolated from 2 Chronic Myelogenous Leukemia (CML) patients and demonstrated to cause neoplastic transformation of NIH3T3 cells. The AXL protein is composed of 894 amino acids in total, wherein the extracellular domain mainly comprises two immunoglobulin-like (IgL) structures and two fibronectin III (FNIII) structures, responsible for binding to its ligand growth arrest-specific protein 6 (Gas 6) and the Pros1 protein of the vitamin K dependent family, involved in the ligand activation pathway of AXL. The Gas6/AXL ligand binding pathway is also the most common pathway for AXL activation, in which the Gas6 protein binds to the AXL receptor to form a Gas6/AXL dimer followed by a 2:2 homodimeric complex with another Gas6/AXL dimer, thus initiating downstream signaling pathway transduction. In addition, AXL receptors can also bind to other AXL receptors in cells or in neighboring cells to form self-dimers, other receptors of the TAM family, and other types of receptors of RTKs and cause their activation. Due to the special function of the AXL receptor, various activation modes and multicellular expression characteristics, the AXL receptor also becomes a hot spot for research in various fields such as tumor immunity, antiviral treatment and the like. At present, cancers related to up-regulation of the expression of the AXL are lung cancer, breast cancer, nasopharyngeal cancer, gastric cancer, colon cancer, liver cancer and the like, so that the cancers have important correlation with occurrence and development of the cancers, and a preparation targeting the AXL possibly has broad-spectrum anti-tumor effect. In addition, AXL is associated with partial cancer metastasis and resistance, and targeting AXL can enhance the therapeutic effects of chemotherapy and other small molecule inhibitors, such as inhibitors of VEGF, EGFR, and HER 2. Currently, existing AXL inhibitors Bemcentinib are FDA approved in a rapid channel-specific manner, and are used in conjunction with PD1/PD-L1 inhibitor Pembrolizumab for the treatment of advanced lung adenocarcinoma patients who have undergone a front line therapy, demonstrating the great potential of AXL inhibitors for clinical use. Development of inhibitors for AXL for cancer targeted therapy currently tends more towards monoclonal antibodies, small molecule inhibitors, etc., but there are some drawbacks that are difficult to overcome, limiting its clinical efficacy. For example, due to the close and similar molecular structures, most of the developed inhibitors of AXL small molecules also inhibit other RTK kinases and have relatively weak effects on AXL, often in combination with other inhibitors for therapeutic use. Although the monoclonal antibody has stronger targeting, the preparation process is complex, the permeability of solid tumor is poor, the research and development cost is high, and the economic burden of clinical application of patients is increased. Therefore, AXL-targeted inhibitors other than small molecule inhibitors and monoclonal antibodies are highly desirable for use in cancer targeted therapies. Based on the above description, there is still a need in the art to develop new drugs or new methods for targeting therapy of AXL receptor and its related tumors to improve the current clinical status. Disclosure of Invention The invention aims to overcome the defects and shortcomings in the prior art and provide a polypeptide with binding affinity to AXL protein and application thereof, and adopts the following technical scheme: In a first aspect of the present invention, there is provided a polypeptide having binding affinity to AXL protein, which is obtained by mutating 12 to 20 (preferably 13 to 16, e.g. 14, 15) amino acids of an amino acid sequence of a Z-segment (Z-domain) of Staphylococcal Protein A (SPA) as a backbone. The polypeptide having binding affinity for the AXL protein is subject to amino acid mutations at positions 9-11,13-14,17-18,24-25,27-28,32,35,43 relative to the amino acid sequence of the Z-segment of the staphylococcal protein A (SEQ ID NO: 1). The sequence of the polypeptide with binding affinity to the AXL protein is shown in SEQ ID NO. 3: the 9 th amino acid is mutated to C; The 10 th amino acid is mutat