US-20260125658-A1 - FUSION PROTEIN CRTZW AND APPLICATION IN CATALYZING PRODUCTION OF ASTAXANTHIN FROM CAROTENE

Abstract

A fusion protein CrtZW and an application in catalyzing a production of astaxanthin from β-carotene are provided, which relates to the field of astaxanthin synthesis technology. The sequence of the fusion protein CrtZW is shown in SEQ ID NO. 4. The fusion protein can catalyze the synthesis of astaxanthin from β-carotene in one step and is suitable for large-scale production.

Inventors

• Siyu Pan
• Fei Yang
• Wei Xiang

Assignees

• Yunnan Vitasource Biological Technology Co., LTD.

Dates

Publication Date

20260507

Application Date

20250930

Priority Date

20241102

Claims (2)

1. 1 . A fusion protein CrtZW, wherein an amino acid sequence of fusion protein CrtZW is SEQ ID NO. 4: MLWIWNALIVFVTVIGMEVIAALAHKYIMHGWGWGWHLSHHEPRKGAFE VNDLYAVVFAALSILLIYLGSTGMWPLQWIGAGMTAYGLLYFMVHDGLV HQRWPFRYIPRKGYLKRLYMAHRMHHAVRGKEGCVSFGFLYAPPLSKLG GGGSGGGGSGGGGSGGGGSEAAAKEAAAKGGGGSGGGGSGGGGSRQTWI GLTLAGMIVAGWGSLHVYGVYFHRWGTSSLVIVPAIVAVQTWLSVGLFI VAHDAMHGSLAPGRPRLNAAVGRLTLGLYAGFRFDRLKTAHHAHHAAPG TADDPDFYAPAPRAFLPWFLNFFRTYFGWREMAVLTALVLIALFGLGAR PANLLTFWAAPALLSALQLFTFGTWLPHRHTDQPFADAHHARSSGYGPV LSLLTCFHFGRHHEHHLTPW, as shown in SEQ ID NO. 4.
2. 2 . An application of the fusion protein CrtZW according to claim 1 in one-step catalytic synthesis of astaxanthin from β-carotene.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202411553439.7, filed on Nov. 2, 2024, which is hereby incorporated by reference in its entirety. SEQUENCE LISTING The present application contains a sequence listing which was filed electronically in XML format and is hereby incorporated by reference in its entirety. Besides, the XML copy is created on Sep. 30, 2025, is named “PA-2025081291-US-Sequence Listing” and is 15,819 bytes in sizes. TECHNICAL FIELD The present disclosure relates to the field of astaxanthin synthesis technologies, and in particular, to a fusion protein CrtZW and an application in catalyzing a production of astaxanthin from β-carotene. BACKGROUND Astaxanthin is a super strong antioxidant that can be applied in fields such as food, health, beauty, and medicine. The production of astaxanthin mainly includes two methods: chemical synthesis and biosynthesis. The biosynthetic sources of astaxanthin include Haematococcus pluvialis, phaffia rhodozyma, Paracoccus, recombinant Escherichia coli, recombinant lipolytic yeast, etc. Astaxanthin has two chiral carbon atoms and three conformations: SS, SR, and RR. Only SS has biological activity. In the chemical synthesis process, the SS conformation accounts for only 25% of the total amount and has low biological activity. The biosynthetic process has a long fermentation time, low product concentration, and high subsequent purification costs. β-carotene can produce astaxanthin through a two-step catalytic reaction: β-carotene produces zeaxanthin under the catalysis of β-carotene hydroxylase, (CrtZ) enzyme, and the zeaxanthin produces astaxanthin under the catalysis of β-carotene ketolase, (CrtW) enzyme; or β-carotene is catalyzed by CrtW enzyme to produce canthaxanthin, and the canthaxanthin is catalyzed by CrtZ enzyme to produce the astaxanthin. The two-step catalytic conversion of β-carotene to produce astaxanthin involves multiple steps, takes a long time, and has a low yield. Therefore, providing an efficient method for catalyzing the production of astaxanthin from β-carotene is an urgent technical problem that technical personnel in this field need to solve. SUMMARY In view of this, the present disclosure provides a fusion protein CrtZW and its application in catalyzing the production of astaxanthin from β-carotene. In order to achieve the above objectives, the present disclosure adopts the following technical solution. A fusion protein CrtZW, where an amino acid sequence of fusion protein CrtZW is SEQ ID NO. 4: MLWIWNALIVFVTVIGMEVIAALAHKYIMHGWGWGWHLSHHEPRKGAF EVNDLYAVVFAALSILLIYLGSTGMWPLQWIGAGMTAYGLLYFMVHDGL VHQRWPFRYIPRKGYLKRLYMAHRMHHAVRGKEGCVSFGFLYAPPLSKL GGGGSGGGGSGGGGSGGGGSEAAAKEAAAKGGGGSGGGGSGGGGSRQTW IGLTLAGMIVAGWGSLHVYGVYFHRWGTSSLVIVPAIVAVQTWLSVGLF IVAHDAMHGSLAPGRPRLNAAVGRLTLGLYAGFRFDRLKTAHHAHHAAP GTADDPDFYAPAPRAFLPWFLNFFRTYFGWREMAVLTALVLIALFGLGA RPANLLTFWAAPALLSALQLFTFGTWLPHRHTDQPFADAHHARSSGYGP VLSLLTCFHFGRHHEHHLTPW, as shown in SEQ ID NO. 4. As an invention concept similar to the above technical solution, the present disclosure further provides an application of the fusion protein CrtZW in one-step catalytic synthesis of astaxanthin from β-carotene. Through the above technical solution, it can be seen that the present disclosure obtains the recombinant fusion protein CrtZW by truncating specific sequences of CrtZ enzyme and CrtW enzyme, and then connecting them through a link sequence. This fusion protein can catalyze the synthesis of astaxanthin from β-carotene in one step, which saves the process flow compared to existing technologies and can be applied to industrial production. BRIEF DESCRIPTION OF DRAWINGS One or more embodiments are illustrated with corresponding drawings, which do not constitute a limitation of the embodiments. Elements with the same reference numerals in the drawings represent similar elements, unless otherwise stated, and the figures in the drawings do not constitute a limitation of proportion. FIG. 1 shows an original structure of CrtZ protein. FIG. 2 shows an original structure of CrtW protein. FIG. 3 shows a structure of Fusion Protein. FIG. 4 shows a comparison of catalytic effects of different enzyme addition methods. FIG. 5 shows a comparison of catalytic effects of different truncation methods for fusion proteins. DESCRIPTION OF EMBODIMENTS The following provides a clear and complete description of the technical solutions in embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, and not all of them. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the protection scope oof the present disclosure. Example 1 Construction of Fusion Protein 1. an original protein sequence of Pantoea ananatis CrtZ has been truncated, and the original sequence is as follows: MLWIWNALIVFVTVIGMEVIA