Anthocyanin biosynthesis is regulated by a conserved transcriptional MBW complex composed of MYB, bHLH and WD40 subunits. However, molecular mechanisms underlying transcriptional regulation of these MBW subunits remain largely elusive. In this study, we isolated an Arabidopsis mutant that displays a constitutive red color in aboveground tissues with retarded growth phenotypes. In the presence of sucrose, the mutant accumulates more than 3-fold anthocyanins of the wild type (WT), but cannot produce anthocyanins as WT in the absence of sucrose. Map-based cloning results demonstrated that the mutation occurs in the locus At4G01000, which encodes a conserved nuclear-localized ubiquitin-like (UBL) superfamily protein, silencing defective 2 (SDE2), in eukaryotes. SDE2 is ubiquitously expressed in various tissues. In the sucrose-induced anthocyanin biosynthesis, SDE2 expression was not responded to sucrose treatment at the early stage but was enhanced at the late stage. SDE2 mutations result in up-regulation of anthocyanin biosynthetic and regulatory genes. Yeast-two hybrid analysis indicated that SDE2 has no direct interaction with the MYB transcription factor PAP1 and bHLH factor TT8, indicating that SDE2 is a indirect factor to affect anthocyanin accumulation. Taking together, our data suggest that SDE2 may play a role in finely coordinating anthocyanin biosynthesis with other biological processes.

The glucagon-like peptide-1 (GLP-1) receptor is currently being explored as a therapeutic target for anti-diabetic drugs. GLP-1 analogs possess therapeutic effects similar to those of other anti-diabetic drugs such as guanidine and sulfonylureas but do not cause hypoglycemia and gastrointestinal discomfort. GLP-1 has the ability to reduce blood glucose in a glucose-dependent manner. Several GLP-1 analog agonists have been developed. However, polypeptide drugs are easily degraded by DPP4 in vivo. Therefore, the focus is now on the development of nonpolypeptide anti-diabetic drugs targeting the GLP-1 receptor. In this study, computer-aided drug design was applied to search for potential molecules of this type. Cochinchinenin C, extracted from sangusis draconi, interacted well with GLP-1 receptor via hydrophobic interaction, which was confirmed by fluorescence spectroscopy and molecular simulation. In cell experiments, it was demonstrated that pancreatic beta cells promoted insulin secretion upon treatment with cochinchinenin C, and increases of intracellular cAMP and ATP levels also occurred, indicating GLP-1 receptor activation and glucose metabolism. These results showed that cochinchinenin C has potential for the development of drugs for treating diabetes.

•We studied the influence of heat treatment on rAra h 2.02.•rAra h 2.02 was heated at boiling (100 °C) or autoclaved (121 °C) for 20 min.•rAra h 2.02 was aggregated after heat treatment.•Binding capacity of 3 core IgE-binding epitopes was changed after heat treatment.The rAra h 2.02 was studied to determine the influence of heat treatment on its structure and core IgE-binding epitopes. The results of SDS–PAGE, Western blotting, MALDI-TOF-MS, and atomic force microscopy showed that the structure of rAra h 2.02 was altered after boiling (100 °C) or autoclaving (121 °C) for 20 min. Furthermore, some of the protein may be aggregated. Results of circular dichroism spectroscopy showed that the α-helices content was reduced, while β-turns and random coils were increased by 81% and 27%, respectively, after autoclaving. Antibodies of three core IgE-binding epitopes were used to determine the binding capacity of rAra h 2.02 after thermal processing by indirect ELISA. The results showed that the binding capacities of the three core IgE-binding epitopes were changed after different heat treatments.

•We studied the effects of thermal processing on Ara h 2.•Ara h 2 was thermal-treated at boiling (100 °C, 15 min), glycation (100 mM Glucose, 100 °C, 15 min), frying (280 °C, 2 min), roasting (170 °C, 15 min).•Allergenicity and structure of Ara h 2 was changed after thermal treatment.•Binding capacity of 3 core epitopes was altered after thermal treatment.Ara h 2 was purified from peanuts that were thermally treated by various processes, including boiling, glycation, frying and roasting. The allergenicity of Ara h 2 in Balb/c mice and the influence of thermal processing on the structural characteristics, and binding capacity of three core antigenic epitopes were studied. The results demonstrated that boiling, glycation and frying induced the down-regulation of the allergenicity of Ara h 2 in Balb/c mice, the collapse of its tertiary/secondary structure, and a reduction in the core epitope binding capacity; roasting showed a comparable allergenicity and the weakest inhibitory effect on core epitope binding capacity. These results indicate that thermal processing causes alteration of the protein structure and core epitopes of Ara h 2, and may affect its allergenicity.

Based on the monoclonal antibodies against 3,3′,5,5′-tetraiodo-L-thyronine (T4), a competitive indirect chemiluminescence enzyme immunoassay (CLEIA) used for the quantitative determination of total T4 in human serum was established. The relevant results indicated that the determined coating antigen concentration was 2.7 μg mL−1 and the CLEIA titer of ascites was 1:8.0 × 104. The standard curve was y = −0.495x + 1.095, with a coefficient of determination, R2 = 0.988, and the derived half inhibition concentration (IC50) of T4 was 16.0 ng mL−1. The system detection limit was 9.23 ng mL−1. The mean inter- and intra-assay variations were 5.89% and 4.02%, respectively. The detected data of total T4 in human serum from seven patients by this method exhibited significant correlation with reported clinical data, suggesting that this CLEIA method could be applicable to the clinical diagnosis of thyroid gland disease.

•We establish a PCR method with IAC for detecting peanut in foods.•We optimise the IAC concentration and make the limit of detection not influenced.•The method can indicate the “false-negative phenomenon” in the experiment.•The method can be applied into universal detection of food allergens.Specific primer sets were designed based on the DNA sequence of Ara h 1, one of the major peanut (Arachis hypogaea) allergens, and a competitive internal amplification control (IAC) was designed by compound primer technology. By choosing 314 copies/PCR as the IAC dosage, a Real-time PCR method with IAC was established for detecting peanut allergen Ara h 1 DNA. The method showed high specificity with a detection limit of 0.005% peanut. A series of commercial food products with/without peanut components were tested. Among these products, the peanut allergen Ara h 1 DNA could be detected in 12 products labelled containing peanut ingredients, in two without a declaration of peanut and one labelled that was produced in a facility that produced peanut-containing foods. This indicates that the method is highly sensitive for the detection of peanut ingredients in foods.

•The interaction between LA (or CC) and human serum albumin has been investigated.•LA and CC quench the HSA fluorescence through a combined quenching.•The binding affinity of CC to HSA was more than that of LA at low concentrations.•LA (or CC) bind to HSA is mainly through hydrogen bonds and van der Waals forces.•The binding study was also modeled by molecular docking.The interactions of loureirin A (LA) and cochinchinenin C (CC) with human serum albumin (HSA) under simulated physiological conditions (pH = 7.4) have been studied with fluorescence, UV–vis absorption spectroscopic method and molecular docking technique. The results indicated that there was a synergistic interaction between LA and CC, and the fluorescence quenching of HSA by LA (or CC) was a combined quenching procedure (dynamic and static quenching). At low compound concentrations, the quenching constants KSV of CC was larger than that of LA, which meant the CC efficacy may be better than that of LA. The negative △H and △S values suggested hydrogen bonds and van der Waals forces played the major role in the binding of LA (or CC) to HSA. The efficiency of energy transfer and distance between the compounds and HSA was calculated. Moreover, the results of synchronous and three-dimensional fluorescence demonstrated that the HSA microenvironment was changed in the presence of LA (or CC). Finally, the binding of LA (or CC) to HSA was modeled by molecular docking, which is in good accordance with the experimental studies.The interaction of loureirin A with human serum albumin has been studied by fluorescence spectroscopic method and molecular docking technique. The quenching constants and mechanism on interactions were determined.

Here, we report the development of a real-time PCR assay using a TaqMan minor groove binder (MGB, Genecore, NCBI: AF249896.1, 806-820) probe and primer sets designed to recognize the α-lactalbumin gene from the cow (Bos taurus). We evaluated the efficacy of this assay for detecting and quantifying cow α-lactalbumin in commercial foods. Our results demonstrated that the developed method was highly sensitive and showed high specificity for cow milk, with consistent detection of 0.05 ng of bovine DNA. We tested 42 commercial food samples with or without cow milk listed as an ingredient by using the developed assay. Among the 42 samples, 26 products that listed milk as an ingredient and 3 products might contain milk showed positive signals, whereas the other 9 products that did not contain milk and 4 products that might contain milk tested negative. Therefore, this method could be widely used for the detection of cow milk allergens in food.