Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China; Research Institute for Future Food, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China.
Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong SAR, China.
Food Res Int. 2022 Oct;160:111670. doi: 10.1016/j.foodres.2022.111670. Epub 2022 Jul 12.
Only a few species of swiftlets in the Aerodramus and Collocalia genera can produce edible bird's nests (EBN). These saliva-cemented nests have been consumed as delicacies for centuries in Asia. Many researches have reported the aqueous extract of EBN has epidermal growth factor-like (EGF-like) activity. However, no standalone EGF has been identified in EBN. Moreover, proteome of EBN remained unclear due to lack of genomic data base of an EBN-producing swiftlet to support proteomic analysis of EBN. To address this, the first genome of the EBN-producing swiftlet, Aerodramus fuciphagus, was constructed. Orthology comparison of A. fuciphagus with 10 other avian species were conducted. The results revealed that the number of predicted paralogous coiled-coil domain-containing protein 63 (CCDC63) coding sequences (CDSs) in A. fuciphagus was found to be significantly expanded in comparison to Gallus gallus. There were 3 paralogous CCDC63 genes in the genome of A.fuciphagus. The CDSs predicted from the genome of A. fuciphagus were used to construct a database for proteomic analysis of EBN. In total, 398 proteins have been identified in EBN. The proteome of EBN was significant enriched with extracellular proteins as well as proteins related to extracellular matrix (ECM) organization and immune response. A few proteins with Ca-binding EGF-like domains were found in the proteome of EBN, like fibrillin-1, protocadherin fat 4 and coagulation factor X. No standalone EGF protein was identified. This indicated that the proteins with EGF-like domains might be responsible for the EGF-like activity of EBN. In addition, acidic mammalian chitinase and lysyl oxidase in EBN were found to be active when extracting with distilled water at room temperature. The current study has not just revealed the species-specific genotype of the EBN-producing swiftlet, A. fuciphagus, but also revealed the proteome of EBN. This established an important foundation for subsequently studies on efficacies of EBN.
仅少数几种金丝燕属（Aerodramus）和短嘴金丝燕属（Collocalia）的燕子能够产生可食用的燕窝（EBN）。这些由唾液黏合而成的燕窝在亚洲已经被食用了几个世纪。许多研究报告称，EBN 的水提物具有表皮生长因子样（EGF-like）活性。然而，在 EBN 中尚未鉴定出单独的 EGF。此外，由于缺乏支持 EBN 蛋白质组分析的 EBN 产生燕子的基因组数据库，因此 EBN 的蛋白质组仍然不清楚。为了解决这个问题，我们构建了第一个 EBN 产生燕子 Aerodramus fuciphagus 的基因组。对 A. fuciphagus 与 10 种其他鸟类的同源性进行了比较。结果表明，与 Gallus gallus 相比，A. fuciphagus 预测的卷曲螺旋结构域-63（CCDC63）编码序列（CDS）的数量显著扩增。A.fuciphagus 基因组中有 3 个同源的 CCDC63 基因。从 A. fuciphagus 基因组中预测的 CDS 被用于构建 EBN 蛋白质组分析的数据库。总共在 EBN 中鉴定出 398 种蛋白质。EBN 的蛋白质组富含细胞外蛋白以及与细胞外基质（ECM）组织和免疫反应相关的蛋白质。在 EBN 的蛋白质组中发现了一些具有 Ca 结合 EGF 样结构域的蛋白质，如原纤维蛋白 1、原钙粘蛋白 fat 4 和凝血因子 X。在 EBN 中未鉴定出单独的 EGF 蛋白。这表明具有 EGF 样结构域的蛋白质可能负责 EBN 的 EGF 样活性。此外，在室温下用蒸馏水提取时，EBN 中的酸性哺乳动物几丁质酶和赖氨酰氧化酶被发现具有活性。本研究不仅揭示了 EBN 产生燕子 A. fuciphagus 的种特异性基因型，还揭示了 EBN 的蛋白质组。这为随后的 EBN 功效研究奠定了重要基础。
