Quantification of silk protein using phage nanofibers with high binding specificity. Issue 24 (23rd April 2020)

• Record Type: Journal Article
• Authors: Ma, Lu; Yang, Tao; Zhai, Mengmeng; Yang, Mingying; Mao, Chuanbin
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 24(2020)
• Page Start: 5189
• Page End: 5194
• Publication Date: 2020-04-23
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Biomedical materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/c9tb01783f
• Languages: English
• ISSNs: 2050-750X

Abstract

Abstract : An ultrasensitive detection strategy for silk sericin (SS) is established by using phage nanofibers displaying SS-binding peptides derived from biopanning. SS concentration is determined by counting the plaques developed from the SS-binding phages. Abstract : Silk sericin (SS) has emerged as an important silk protein for use in medicine and textiles. However, no sensitive method is available for detecting it. Here, we employed phage nanofibers (∼7 nm wide) as a probe to quantify SS from a dilute aqueous solution by exploiting two properties of the bacteria-infecting phage nanofibers, its use as a platform for discovering SS-binding peptide and its ultrasensitive quantification by a simple titering assay (where the number of phage nanofibers displaying the SS-binding peptide is equal to the number of countable millimeter-sized plaques derived from the phage nanofibers by infecting bacteria through plating). We first discovered a SS-binding peptide and the phage nanofibers (SS-phage) displaying this peptide at the tip. We found that this peptide can even differentiate SS from another silk protein (silk fibroin), showing its high specificity. We then employed SS-phage nanofibers as a probe to bind the SS casted from the aqueous solution. Because SS-phage nanofibers bound to the SS and the SS in the original SS solution were numerically correlated and the number of SS-phage nanofibers can be determined by counting the plaques in a Petri dish by the titering assay, determining the number of phage-derived plaques with the naked eye led to the rapid quantification of SS concentration with a detection limit of 19.50 ng ml −1 . This phage-based counting strategy can be potentially applied to the facile detection of other proteins.