METHODS: Ten ligands with reported in vitro and/or in vivo activities against GAPDH were evaluated for their binding interactions through molecular docking studies using AutoDock 4.2 program. The ligand with the best binding energy was then modified to produce 10 derivatives, which were redocked against GAPDH using previous protocols. BIOVIA Discovery Studio Visualizer 2019 was used to explore the ligand-receptor interactions between the derivatives and GAPDH.
RESULTS: Among the 10 ligands, curcumin, koningic acid and folic acid showed the best binding energies. Further analysis on the docking of two folic acid derivatives, F7 (γ-{[tert-butyl-N-(6-aminohexyl)]carbamate}folic acid) and F8 (folic acid N-hydroxysuccinimide ester) showed that the addition of a bulky substituent at the carboxyl group of the glutamic acid subcomponent resulted in improved binding energy.
CONCLUSIONS: Folic acid and the two derivatives F7 and F8 have huge potentials to be developed as targeting agents against the GAPDH receptor. Further study is currently on-going to evaluate the effectiveness of these molecules in vitro.
EXPERIMENTAL APPROACH: The chemical composition of the OCS02® cold water extract was determined, and the antioxidant activities were examined using ferric reducing, DPPH• and O2 •- scavenging assays. Tetrazolium dye (MTT) cytotoxic assay was performed to assess the antiproliferative activity of the extract. Bioactive proteins in the active fraction of the extract were identified using liquid chromatography (LC) and tandem-mass spectrometry (MS/MS).
RESULTS AND CONCLUSIONS: The OCS02® extract exhibited strong O2 •- scavenging (expressed as Trolox equivalents (18.4±1.1) mol/g) and potent cytotoxic activities against adenocarcinomic human alveolar basal epithelial (A549) cells (IC50=(58.2±6.8) µg/mL). High molecular mass polysaccharides, proteins and protein-polysaccharide complexes could have contributed to the antioxidant and cytotoxic selectivity of the OCS02®. LC-MS/MS analysis identified several potential cytotoxic proteases and an oxalate decarboxylase protein which may exhibit protection effects on kidneys.
NOVELTY AND SCIENTIFIC CONTRIBUTIONS: The findings demonstrate the potential of OCS02® to be developed into functional food due to its promising superoxide anion radical scavenging capacity, cytotoxic effect and presence of biopharmaceutically active proteins.
METHODS: A total of 312 women were randomly divided into two groups with 156 participants each group. In Group A, ASP medium was used during ET, whereas in Group B, no ASP medium was utilized. Positive implantation was defined as serum beta-hCG level >5 mIU/mL taken on the 7th day following ET.
RESULTS: The average age of the majority of the participants was 30-39 years and had at least 4-5 years of subfertility. The unexplained subfertility was the prominent cause of ET failure in both groups. In most of the participants in both groups, ET was done using fresh embryo cycles with good to excellent embryo grades. After the ASP medium was manipulated in the OC in both groups, the positive implantation rate was not different in both groups (p>0.05).
CONCLUSIONS: The elimination of air bubbles in OC by using the ASP medium during ET did not confer an additional benefit nor exert a negative impact on implantation rate.
BACKGROUND: High background signals resulting from nonspecific binding are a significant concern for microtiter plate-based enzyme-linked lectin sorbent assays (ELLSAs), as they can mask specific binding signals and cause false-positive results.
METHODS: In this study, we constructed an ELLSA based on different washing step parameters, including the number of washing cycles, NaCl and Tween-20 concentrations, and the type of blocking agent and evaluated the effects on both specific and nonspecific binding signals. Furthermore, we performed a PSA binding assay using the optimized ELLSA.
RESULTS: The optimal washing parameters based on the highest specific binding signal proposed four cycles of washing steps using a washing buffer containing a high salt concentration (0.5 M NaCl) and mild detergent (0.05% Tween-20). The utilization of the optimized washing parameters in this assay was shown to be sufficient to obtain the optimal binding signals without the use of any blocking agent. Binding assays performed using the optimized ELLSA revealed that the glycan of the PSA sample used in this study mainly consists of terminal α2,6-linked sialic acid, as strongly recognized by Sambucus nigra agglutinin (SNA) with a KD value of 12.38 nM.
CONCLUSION: The ELLSA reported in this study provides a simple yet sensitive assay for sialic acid linkage recognition.