We attempted to develop a novel method for the chemical modification of cytokines with synthetic polymers to increase in vivo therapeutic efficacy. A pH-reversible amino-protective reagent, dimethylmaleic anhydride (DMMAn), was used for polymer conjugation of tumor necrosis factor-alpha (TNF-alpha) with polyethylene glycol (PEG). The novel PEGylated TNF-alpha, PEG-TNF-alpha(+), which was pretre...

A simple micro (0.1 ml.) colorimetric method is described for the determination of serum calcium. This method employs the differential chelating characteristic of glyoxyl bis (2-hydroxyanil) in the presence of other divalent cations. The serum sample is placed in a colorimetric tube followed by additions of water, glyoxyl bis (2-hydroxyanil) reagent, and alkaline carbonate color developer. Chlo...

Here, we report a generally applicable PEGylation methodology based on the site-specific incorporation of para-azidophenylalanine into proteins in yeast. The azido group was used in a mild [3+2] cycloaddition reaction with an alkyne derivatized PEG reagent to afford selectively PEGylated protein. This strategy should be useful for the generation of selectively PEGylated proteins for therapeutic...

Monomeric cytochrome f from Japanese radish (Raphanus sativus L. var acanthiformis Makino) leaves was isolated in a homogeneous state with an A420.5/A277 of 7.6. Radish cytochrome f is a single polypeptide chain with a molecular weight of about 33,000. The midpoint potential is 350 mV. The amino acid analysis indicates the existence of 3 residues of half-cystine. Radish cytochrome f contains on...

Because various non-parallel G-quadruplexes of human telomeric sequences in K+ solution can be converted to a parallel G-quadruplex by adding polyethylene glycol (PEG) as a co-solvent, we have taken advantage of this property of PEG to study the covalent attachment of a PEG unit to a G-quadruplex ligand, 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide (BMVC). The hybrid ligand with the P...

the reaction of tertiary, secondary and benzylic alcohols with different nitriles in the presence of alumina-methanesulfonic acid (ama) as a new reagent affords the corresponding amides in good yields (table 1, 2). conversion of 2,6-bis(hydroxymethyl)-4-halo anisoles into corresponding diamides in the range of 68-76% yields (table 3) are also included in this paper.

2-monobromomethyl 1,4-dihydropyridines is selectively synthesized by bromination of the parent compound by 1.1 equivalents of pyridinium bromide perbromide in dichloromethane/pyridine at -20 °c. the same reagent in dichloromethane at 0 °c produce the 2,6-bis(bromomethyl) 1,4-dihydropyridines.

The properties of two carnitine acyltransferases (CPT) purified from bovine liver are compared to confirm that they are different proteins. The soluble CPT and the inner CPT from mitochondria differ in subunit Mr, native Mr, pI and reactivity with thiol reagents. All eight free thiol groups in soluble CPT react with 5,5'dithiobis-(2-nitrobenzoate) in the absence of any unfolding reagent, and ac...

The direct trifluoromethylation of a variety aliphatic alcohols using hypervalent iodosulfoximine reagent afforded the corresponding ethers in moderate to good yields (14–72 %). Primary, secondary, and even tertiary alcohols, including examples derived from natural products, underwent this transformation presence catalytic amounts zinc bis(triflimide). Typical reaction conditions involved neat ...

Apurinic/apyrimidinic (AP) endonuclease 1 (APE1) is the primary enzyme in mammals for the repair of abasic sites in DNA, as well as a variety of 3' damages that arise upon oxidation or as products of enzymatic processing. If left unrepaired, APE1 substrates can promote mutagenic and cytotoxic outcomes. We describe herein a dominant-negative form of APE1 that lacks detectable nuclease activity a...