Optimized Bioorthogonal Non-canonical Amino Acid Tagging to Identify Serotype-Specific Biomarkers in Verotoxigenic Escherichia coli

A chitosan-integrated antibacterial protein composite nanocomplex derived from barnacle cement and spider silk

While barnacle cement protein cp19k (from Megabalanus rosa) possesses remarkable adhesion properties and spider silk protein MaSp1 (from Nephila clavata dragline silk) demonstrates exceptional toughness, their advancements in medical biomaterials are significantly hindered by their limitations in antimicrobial properties. In this study, composite nanocomplexes incorporating chitosan and proteins derived from barnacle cement and spider silk were designed and biofabricated for enhanced antibacterial properties. The impact of chitosan's molecular weight on the properties of nanocomplexes comprising cp19k-MaSp1/chitosan, MaSp1/chitosan, and cp19k/chitosan was evaluated. The results revealed that low molecular weight chitosan (LMWC, Mw = 1 kDa) forms nanocomplexes that exhibit distinct structural differences in comparison to those formed with high molecular weight chitosan (HMWC, Mw ≥ 150 kDa). Furthermore, cp19k-MaSp1/C150k exhibited the most potent antibacterial activity against E. coli and S. aureus, surpassing the performance of cp19k, MaSp1, cp19k-MaSp1, and chitosan individually, achieving inhibition by disrupting the bacterial cell membrane structure and elevating the intracellular ROS level. Meanwhile, On day 6, the viability of HUVECs (Human Umbilical Vein Endothelial Cells) of cp19k-MaSp1/C150k had attained a level of 145.21 ± 6.23 %, representing a substantial elevation when compared to C150k. The remarkable biocompatibility of nanocomplexes cp19k-MaSp1/C150k holds potential for application in wound dressings and tissue repair.

Engineered Proteins and Materials Utilizing Residue-Specific Noncanonical Amino Acid Incorporation

The incorporation of noncanonical amino acids into proteins and protein-based materials has significantly expanded the repertoire of available protein structures and chemistries. Through residue-specific incorporation, protein properties can be globally modified, resulting in the creation of novel proteins and materials with diverse and tailored characteristics. In this review, we highlight recent advancements in residue-specific incorporation techniques as well as the applications of the engineered proteins and materials. Specifically, we discuss their utility in bio-orthogonal noncanonical amino acid tagging (BONCAT), fluorescent noncanonical amino acid tagging (FUNCAT), threonine-derived noncanonical amino acid tagging (THRONCAT), cross-linking, fluorination, and enzyme engineering. This review underscores the importance of noncanonical amino acid incorporation as a tool for the development of tailored protein properties to meet diverse research and industrial needs.

Progress in methods for the detection of viable Escherichia coli

Escherichia coli (E. coli) is a prevalent enteric bacterium and a necessary organism to monitor for food safety and environmental purposes. Developing efficient and specific methods is critical for detecting and monitoring viable E. coli due to its high prevalence. Conventional culture methods are often laborious and time-consuming, and they offer limited capability in detecting potentially harmful viable but non-culturable E. coli in the tested sample, which highlights the need for improved approaches. Hence, there is a growing demand for accurate and sensitive methods to determine the presence of viable E. coli. This paper scrutinizes various methods for detecting viable E. coli, including culture-based methods, molecular methods that target DNAs and RNAs, bacteriophage-based methods, biosensors, and other emerging technologies. The review serves as a guide for researchers seeking additional methodological options and aiding in the development of rapid and precise assays. Moving forward, it is anticipated that methods for detecting E. coli will become more stable and robust, ultimately contributing significantly to the improvement of food safety and public health.