Anti-Acetyl-Lysine monoclonal antibody, clone 26H20

This report describes the first synthesis and application of a fluorescent teixobactin analogue that exhibits antibiotic activity and binds to the cell walls of Gram-positive bacteria. The teixobactin analogue, Lys(Rhod)(9),Arg(10)-teixobactin, has a fluorescent tag at position 9 and an arginine in place of the natural allo-enduracididine residue at position 10. The fluorescent teixobactin analogue retains partial antibiotic activity, with minimum inhibitory concentrations of 4-8 mu g/mL across a panel of Gram-positive bacteria, as compared to 1-4 mu g/mL for the unlabeled Arg(10)-teixobactin analogue. Lys(Rhod)(9),Arg(10)-teixobactin is prepared by a regioselective labeling strategy that labels Lys(9) with an amine-reactive rhodamine fluorophore during solid-phase peptide synthesis, with the resulting conjugate tolerating subsequent solid-phase peptide synthesis reactions. Treatment of Gram-positive bacteria with Lys(Rhod)(9),Arg(10)-teixobactin results in septal and lateral staining, which is consistent with an antibiotic targeting cell wall precursors. Concurrent treatment of Lys(Rhod)(9),Arg(10)-teixobactin and BODIPY FL vancomycin results in septal colocalization, providing further evidence that Lys(Rhod)(9),Arg(10)-teixobactin binds to cell wall precursors. Controls with either Gram-negative bacteria, or an inactive fluorescent homologue with Gram-positive bacteria, showed little or no staining in fluorescence micrographic studies. Lys(Rhod)(9),Arg(10)-teixobactin can thus serve as a functional probe to study Gram-positive bacteria and their interactions with teixobactin.

In order to investigate the influences of ultrasonic-assisted frying on the flavor characteristics of fried meatballs, different ultrasound powers (0, 200, 400, 600 and 800 W) were applied during frying (12 min, 160 degrees C). The thiobarbituric acid reactive substances (TBARS), free fatty acids (FFAs), free amino acids (FAAs), 5'-ribonucleotides and electronic nose data were measured. Results demonstrated that ultrasonic treatment significantly increased TBARS and decreased Sigma FFAs (p < 0.05), thus accelerating FFAs oxidation and further promoting volatiles generation. Meanwhile, ultrasonic-assisted frying increased the contents of 7 FAAs including Lys, Glu, Gly, Ala, Tyr, Ser and Cys in all ultrasonic groups and had a positive effect on nucleotides formation within 400 W. These results were further confirmed by electronic nose analysis. The current study shows that ultrasonic-assisted frying could be a potential approach to improve the overall flavor of fried meatballs. Industrial relevance: Ultrasound, as an emerging and green technology, is a safety and effective tool for food processing industry. It is considered as an excellent alternative in meat processing. Ultrasonic-assisted frying has been scarcely applied in the processing of meatballs. This study demonstrated that the flavor quality of meatballs improved a lot by ultrasonic treatment, which could be an ideal reference to optimize its application in meat industry.