Bio‐nanocapsule‐based scaffold improves the sensitivity and ligand‐binding capacity of mammalian receptors on the sensor chip. Issue 6 (20th April 2016)

• Record Type: Journal Article
• Authors: Iijima, Masumi; Yoshimoto, Nobuo; Niimi, Tomoaki; Maturana, Andrés D.; Kuroda, Shun'ichi
• Is Part Of: Biotechnology journal. Volume 11:Issue 6(2016)
• Page Start: 805
• Page End: 813
• Publication Date: 2016-04-20
• Subjects: Bio‐nanocapsules -- Biosensors -- IgG Fc‐fused receptors -- Oriented immobilization -- Quartz crystal microbalance; Biotechnology -- Periodicals; 660.605
• DOI: 10.1002/biot.201500443
• Languages: English
• ISSNs: 1860-6768

Abstract

Abstract: Mammalian receptors are recognized as target molecules for drug discovery, and chemical libraries have been screened for both potential antagonists and agonists mainly by ligand‐binding assays using immobilized receptors. A bio‐nanocapsule (BNC) of approximately 30 nm that displays a tandem form of the protein A‐derived immunoglobulin G (IgG) Fc‐binding Z domains (denoted as ZZ‐BNC) has been developed for both clustering and oriented immobilization of IgGs on the solid phase of immunosensors. In this study, human IgG1 Fc‐fused vascular endothelial growth factor (VEGF) receptor was immobilized through ZZ‐BNC on the sensor chip of quartz crystal microbalance (ZZ‐BNC‐coating). When compared with direct adsorption and protein A‐coating, the sensor chip showed higher sensitivity (∽46‐ and ∽165‐fold, respectively) and larger ligand‐binding capacity (∽4‐ and ∽18‐fold, respectively). Furthermore, the number of VEGF molecules bound to its receptor increased from 0.20 (direct adsorption) to 2.06 by ZZ‐BNC‐coating, strongly suggesting that ZZ‐BNC reduced the steric hindrance near ligand recognition sites through oriented immobilization. Similarly, the sensitivity and ligand‐binding capacity of leptin and prolactin receptors were both enhanced at a level comparable to that observed for the VEGF receptor. Thus, the combination of ZZ‐BNC and Fc‐fused receptors could significantly improve the function of ligand‐binding assays. Abstract : Bio‐nanocapsule (BNC)‐based scaffold for ligand‐binding assays: Experimental evidence from the current study demonstrates that ZZ‐BNC displaying IgG Fc‐binding Z domains outwardly can act as a scaffold for the clustering and oriented immobilization of Fc‐fused receptors. ZZ‐BNC‐coated sensor chips appeared to improve the sensitivity and ligand‐binding capacity of various ligand‐binding assays significantly rather than bare and protein A‐coated sensor chips. This article is part of an AFOB (Asian Federation of Biotechnology) Special issue. To learn more about the AFOB, visitwww.afob.org .