PMID- 38185034 OWN - NLM STAT- MEDLINE DCOM- 20240208 LR - 20240208 IS - 1878-1705 (Electronic) IS - 1567-5769 (Linking) VI - 128 DP - 2024 Feb 15 TI - Artificial intelligence-driven design of the assembled major cat allergen Fel d 1 to improve its spatial folding and IgE-reactivity. PG - 111488 LID - S1567-5769(24)00005-5 [pii] LID - 10.1016/j.intimp.2024.111488 [doi] AB - BACKGROUND: Cat-derived allergens are considered as one of the most common causes of allergic diseases worldwide. Fel d 1 is a major cat allergen and plays an important role in immunoglobulin E (IgE)-reaction diagnosis. However, the two separate chains of Fel d 1 exhibited lower IgE-reactivity than its complete molecule of an assembled form, which makes it difficult to efficiently prepare and limits the application of Fel d 1 in molecular diagnosis of cat allergy. METHODS: We first applied artificial intelligence (AI) based tool AlphaFold2 to build the 3-dimensional structures of Fel d 1 with different connection modes between two chains, which were evaluated by ERRAT program and were expressed in Escherichia coli. We then calculated the expression ratios of soluble form/inclusion bodies form of optimized Fel d 1. The Circular Dichroism (CD), High Performance Liquid Chromatography-Size Exclusion Chromatography (HPLC-SEC) and reducing/non-reducing SDS-PAGE were performed to characterize the folding status and dimerization of the optimized fusion Fel d 1. The improvement of specific-IgE reactivity to optimized fusion Fel d 1 was investigated by enzyme linked immunosorbent assay (ELISA). RESULTS: Among several linkers, 2 x GGGGS got the highest scores, with an overall quality factor of 100. The error value of the residues around the junction of 2 x GGGGS was lower than others. It exhibited highest proportion of soluble protein than other Fel d 1 constructs with ERRAT (GGGGS, KK as well as direct fusion Fel d 1). The results of CD and HPLC-SEC showed the consistent folding and dimerization of two fused subunits between the optimized fusion Fel d 1 and previously well-defined direct fusion Fel d 1. The overall IgE-binding absorbance of optimized fusion Fel d 1 tested by ELISA was improved compared with that of the direct fusion Fel d 1. CONCLUSION: We firstly provided an AI-design strategy to optimize the Fel d 1, which could spontaneously fold into its native-like structure without additional refolding process or eukaryotic folding factors. The improved IgE-binding activity and simplified preparation method could greatly facilitate it to be a robust allergen material for molecular diagnosis of cat allergy. CI - Copyright (c) 2024 Elsevier B.V. All rights reserved. FAU - Zheng, Wei AU - Zheng W AD - Department of Pharmacy, Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research & The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, China. FAU - Xu, Yi-Fei AU - Xu YF AD - Department of Pharmacy, Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research & The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, China. FAU - Hu, Zhi-Ming AU - Hu ZM AD - Department of Pharmacy, Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research & The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, China. FAU - Li, Ke AU - Li K AD - Department of Pharmacy, Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research & The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, China. FAU - Xu, Zhi-Qiang AU - Xu ZQ AD - Research Division of Clinical Pharmacology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China; National Vaccine Innovation Platform, Nanjing Medical University, Nanjing 211166, China. Electronic address: xu.zhiqiang@outlook.com. FAU - Sun, Jin-Lyu AU - Sun JL AD - Department of Allergy, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China. Electronic address: sunjinlv@pumch.cn. FAU - Wei, Ji-Fu AU - Wei JF AD - Department of Pharmacy, Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research & The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, China; Research Division of Clinical Pharmacology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China; National Vaccine Innovation Platform, Nanjing Medical University, Nanjing 211166, China. Electronic address: weijifu@njmu.edu.cn. LA - eng PT - Journal Article DEP - 20240106 PL - Netherlands TA - Int Immunopharmacol JT - International immunopharmacology JID - 100965259 RN - 37341-29-0 (Immunoglobulin E) RN - 0 (Allergens) SB - IM MH - Humans MH - *Immunoglobulin E/metabolism MH - Amino Acid Sequence MH - Artificial Intelligence MH - *Hypersensitivity MH - Allergens/chemistry OTO - NOTNLM OT - Allergen OT - Artificial intelligence OT - Escherichia coli OT - Fel d 1 OT - Immunoglobulin E (IgE) COIS- Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. EDAT- 2024/01/08 00:42 MHDA- 2024/02/08 06:42 CRDT- 2024/01/07 18:11 PHST- 2023/10/16 00:00 [received] PHST- 2023/12/31 00:00 [revised] PHST- 2024/01/02 00:00 [accepted] PHST- 2024/02/08 06:42 [medline] PHST- 2024/01/08 00:42 [pubmed] PHST- 2024/01/07 18:11 [entrez] AID - S1567-5769(24)00005-5 [pii] AID - 10.1016/j.intimp.2024.111488 [doi] PST - ppublish SO - Int Immunopharmacol. 2024 Feb 15;128:111488. doi: 10.1016/j.intimp.2024.111488. Epub 2024 Jan 6.