Monitoring complex endocrine pathways is often limited by indirect measurement or measurement of a single hormone class per analysis. There is a burgeoning need to develop specific direct-detection methods capable of providing simultaneous measurement of biologically relevant concentrations of multiple classes of hormones (estrogens, androgens, progestogens, and corticosteroids). The objectives...

The NS2B-NS3(pro) polyprotein segment from the dengue virus serotype 2 strain 16681 was purified from overexpressing E. coli by metal chelate affinity chromatography and gel filtration. Enzymatic activity of the refolded NS2B-NS3(pro) protease complex was determined in vitro with dansyl-labeled peptide substrates, based upon native dengue virus type 2 cleavage sites. The 12mer substrate peptide...

The reduction potentials (E(h)) for the redox couples GSH/GSSG and cysteine/cystine (Cys/CySS) in plasma are useful indicators of systemic oxidative stress and other medically relevant physiological states. This article describes a sensitive method for determining plasma levels of GSH, GSSG, Cys, and CySS used to calculate the in vivo E(h) values. The method uses iodoacetate to alkylate free th...

The design, synthesis and application of a new fluorescent-labeling reagent for collagen has been developed as a prerequisite for the design of a photoactivated collagen-crosslinking compound for surgical wound closure. The amine groups in collagen are the targets of a rational design for a new fluorophore because natural collagen crosslinks are formed between primary (1(o)) amine groups of lys...

Treatment of dogfish l& lactic dehydrogenase with carboxypeptidase A releases 1 mole of phenylalanine per 36,000 g of the enzyme and no other amino acids. A mixture of carboxypeptidases A and B releases 1 mole of phenylalanine and 1 mole of lysine per 36,000 g of the lactic dehydrogenase. The amino terminus of dogfish M4 lactic dehydrogenase does not react with either dansyl chloride or the Edm...

Biogenic amines (BAs), that is, spermine, spermidine, putrescine, histamine, tyramine, β-phenylethylamine, cadaverine, and serotonin, have been determined in several samples of tea leaves, tea infusions, and tea drinks by LC-UV method after derivatization with dansyl chloride. Different extraction solvents have been tested and TCA 5% showed better analytical performances in terms of linearity, ...

Novel bichromophoric fluorescent photolabile protecting group, (5-dansyloxy-3-hydroxynaphthalen-2-yl)methyl (DNS-NQMP), allows for the independent photochemical release and fluorescent imaging of caged substrates. Irradiation of DNS-NQMP-caged alcohols and carboxylic acids with 300 or 350 nm light results in fast (k(release) ~ 10(5) s(-1)), efficient (Φ = 0.2), and quantitative release of the s...

The structure of an ornithine-containing lipid from Z’Gobacillus fhiooxidans has been elucidated. Methanolysis of the lipid released methyl cis-ll,lZ-methylene-Z-hydroxyoctadecanoate. Acid hydrolysis of the residue yielded ornithine and a mixture of fatty acids, the major components of which were 3-hydroxyhexadecanoic and 2-hexadecenoic acids. Identification of the 3-hydroxy fatty acid was base...