Nanobodies (Nbs) are widely used in immunoassays with the advantages of small size and high stability. Here, the nanobody employed as the surrogate of aflatoxin antigen and the recognition mechanism of antiaflatoxin mAb with nanobody was studied by molecular modeling, which verified the feasibility of Nbs as antigen substitutes. On this basis, a nanobody-alkaline phosphatase fusion protein (Nb-AP) was constructed, and a highly sensitive "on-off-on" fluorescent immunosensor (OFO-FL immunosensor) based on the calcein/Ce system was developed for aflatoxin quantification. Briefly, calcein serves as a signal transducer, and its fluorescence can be quenched after it is bound with Ce. In the presence of Nb-AP, AP catalyzed p-nitrophenyl phosphate to generate orthophosphate, which competes in binding with Ce, leading to fluorescence recovery. The method has a linearity range of 0.005-100 ng/mL, and the IC of the OFO-FL immunosensor was 0.063 ng/mL, which was 18-fold lower than that of conventional enzyme-linked immunosorbent assay. The assay was successfully applied in food samples with a recovery of 88-121%.
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http://dx.doi.org/10.1021/acs.jafc.3c05376 | DOI Listing |
PLoS One
January 2025
Instituto de Investigación en Ciencias Biomédicas, Centro Universitario de Ciencias de la Salud Universidad de Guadalajara, Guadalajara, Mexico.
Studies have noted the connection between Mycobacterium avium subspecies paratuberculosis (MAP) and autoimmunity. MAP is an intracellular pathogen that infects and multiplies in macrophages. To overcome the hostile environment elicited by the macrophage, MAP secretes a battery of virulence factors to neutralize the toxic effects of the macrophage.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
School of Life Sciences and Health Engineering, Jiangnan University, Jiangsu, 214122, China.
Dysfunction in the SHP1 enzyme can cause cancers and many diseases, so it is of great significance to develop novel small molecule SHP1 inhibitors. Through continuous monitoring of metabolic and targeted processes of SHP1 inhibitors in real-time, we can evaluate the effectiveness and toxicity of the inhibitors, further optimize drug design, and explore SHP1 biology. Indoloquinoxaline is an important class of N-containing heterocycle, which has been studied and applied in the pharmacological field and in optoelectronic materials.
View Article and Find Full Text PDFMed Mol Morphol
December 2024
Graduate School, Tianjin Medical University, Tianjin, 300070, China.
Ankylosing spondylitis (AS) is a chronic inflammatory disease involving the spine and bone joints, which is characterized by hyperosteogeny, ossification of ligaments, and ankylosis. Quercetin is a natural polyphenolic compound with various biological activities such as antioxidant, anti-inflammatory, and anti-tumor. It was to explore the effect of quercetin on AS ossification and its molecular mechanism.
View Article and Find Full Text PDFJ Med Case Rep
December 2024
Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nakagami, Nishihara, Okinawa, 903-0215, Japan.
Background: Adult hypophosphatasia is an uncommon inherited disorder of mineral homeostasis affecting bone. It arises from mutations within the Alkaline Phosphatase, Biomineralization Associated (ALPL) gene, which encodes tissue-nonspecific alkaline phosphatase. Because of its low prevalence and non-specific clinical manifestations, underdiagnosis and misdiagnosis are frequent, particularly in Asian populations.
View Article and Find Full Text PDFAnal Chem
December 2024
College of Stomatology, Hospital of Stomatology/Guangxi Key Laboratory of Nanobody Research/Guangxi Nanobody Engineering Research Center/School of Basic Medical Sciences/Affiliated Tumor Hospital, Guangxi Medical University, Nanning, Guangxi 530021, China.
The continuous spread and evolution of severe acute respiratory symptom coronavirus 2 (SARS-CoV-2) necessitate the development of convenient and rapid detection methods. In this study, we developed a fluorescence enzyme immunoassay (FEIA) based on a nanobody (Nb)-alkaline phosphatase (ALP) fusion protein for detection of SARS-CoV-2 spike protein. The genetically modified anti-SARS-CoV-2 S-RBD Nb, Nb61, gene was fused with the ALP gene sequences via a flexible linker.
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