Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe 657-8501, Japan.
J Biotechnol. 2012 Jan;157(1):124-9. doi: 10.1016/j.jbiotec.2011.09.015. Epub 2011 Sep 22.
Bio-nanocapsules (BNCs) are hollow nanoparticles composed of the L protein of hepatitis B virus (HBV) surface antigen (HBsAg), which can specifically introduce genes and drugs into various kinds of target cells. Although the classic electroporation method has typically been used to introduce highly charged molecules such as DNA, it is rarely adopted for proteins due to its very low efficiency. In this study, a novel approach to the preparation of BNC was established whereby a target protein was pre-encapsulated during the course of nanoparticle formation. Briefly, because of the process of BNC formation in a budding manner on the endoplasmic reticulum (ER) membrane, the association of target proteins to the ER membrane with lipidation sequences (ER membrane localization sequences) could directly generate protein-encapsulating BNC in collaboration with co-expression of the L proteins. Since the membrane-localized proteins are automatically enveloped into BNCs during the budding event, this method can be protect the proteins and BNCs from damage caused by electroporation and obviate the need for laborious consideration to study the optimal conditions for protein encapsulation. This approach would be a useful method for encapsulating therapeutic candidate proteins into BNCs.
生物纳米胶囊（BNCs）是由乙型肝炎病毒（HBV）表面抗原（HBsAg）的 L 蛋白组成的中空纳米颗粒，它可以将基因和药物特异性地导入各种靶细胞。虽然经典的电穿孔法通常用于引入带高电荷的分子，如 DNA，但由于效率非常低，很少用于蛋白质。在本研究中，建立了一种制备 BNC 的新方法，其中在纳米颗粒形成过程中预先包封靶蛋白。简而言之，由于 BNC 以出芽的方式在内质网（ER）膜上形成，带有脂化序列（ER 膜定位序列）的靶蛋白与 ER 膜的结合可以直接生成与 L 蛋白共表达的蛋白包封的 BNC。由于在出芽事件中膜定位蛋白自动被包裹在 BNC 中，因此该方法可以保护蛋白和 BNC 免受电穿孔引起的损伤，并且无需费力考虑研究蛋白包封的最佳条件。该方法将是将治疗候选蛋白包封到 BNC 中的有用方法。
