Cytochrome c Oxidase
René Lontie in Copper Proteins and Copper Enzymes, 1984
In analogy with these findings it was assumed that the proton-translocating mechanism of the oxidase possibly utilizes carboxyl groups in hydrophobic environments. Reaction of the isolated or vesicle-incorporated enzyme revealed dicyclohexylcarbodiimide reaction sites only at subunits II, III, and IV.173,174 Under stringent conditions the reconstituted enzyme was only blocked at the mitochondrial subunit III at one174 or several173 residues. This, thus, may be one coupled end between electron transfer and proton translocation. Among the dicyclohexylcarbodiimide-binding residues so far identified in this subunit is Glu-90 which is included in the second hydrophobic domain of this polypeptide in an amino-acid sequence similar to that found in the ATP-synthase proteolipid.173 It seems, however, necessary to remind that the two mitochondrial antidirectional proton fluxes considered in this analogy represent different biochemical devices.
Methods of Protein Iodination
Erwin Regoeczi in Iodine-Labeled Plasma Proteins, 2019
The method takes its origin from an observation made in peptide synthesis, namely, that because of the water solubility of N-hydroxysuccinimide, the resulting esters are more convenient to use than those of N-hydroxyphthalimide.136 The ester bond between the propionic acid and the hydroxyimide can be established136,137 by the carbodiimide technique, e. g., by using dicyclohexylcarbodiimide, with approximately one third yield. The ester is also available commercially. Its molecular weight (before halogenation) is 263.25.
Conjugation of Polymers with Biomolecules and Polymeric Vaccine Development Technologies
Mesut Karahan in Synthetic Peptide Vaccine Models, 2021
Dicyclohexylcarbodiimide is a commonly used cross-linker, especially in organic synthesis applications. It has been used in peptide synthesis since 1955. DCC is soluble in organic solvents and can be used at temperatures of up to 80°C (Hermanson 1996; Hermanson 2013).
Modulating effect of a new ester, 28-O-phosphatidylbetulin (DAPB), obtained from hen egg yolk lecithin and betulin on lymphocyte subsets and humoral immune response in mice
Published in Immunopharmacology and Immunotoxicology, 2019
Magdalena Lis, Barbara Barycza, Angelika Sysak, Aleksandra Pawlak, Agnieszka Suszko-Pawłowska, Marianna Szczypka, Czesław Wawrzeńczyk, Bożena Obmińska-Mrukowicz
28-O-(1,2-diacyl-sn-glycero-3-phospho)-betulin (DAPB) was synthesized in a one-step reaction, via phosphatidic acid (DAPA) esterification with betulin with 86% yield (Scheme 1). The esterification was chemo- and stereoselective and gave only a single product. The reaction was carried out in pyridine with N,N'-dicyclohexylcarbodiimide (DCC) as a coupling agent, in the presence of 4-dimethylamino-pyridine (DMAP). 1,2-diacyl-sn-glycero-3-phosphatidic acid (DAPA) used in this synthesis was a product of enzymatic hydrolysis of phosphatidylcholine (isolated from egg-yolk of Lohmann Brown hens) with phospholipase D from Streptomyces chromofuscus. Enzymatic reaction resealed phosphatidic acid (DAPA) with 65% yield. The composition of fatty acids of phosphatidic acid (DAPA) according to GC was as follows: 16:0 (32.2%), 16:1 (1.1%), 18:0 (16.9%), 18:1 (28.6%), 18:2 (16.7%), 20:4 (2.6%), 22:6 (1.9%) (Scheme 2). Betulin was isolated from the bark of Betula pendula Roth and purified (22% yield) according to the previously described procedure [18]. The physicochemical properties and spectroscopic data were compared with a standard for betulin (98%), purchased from Sigma–Aldrich (Germany). Betulin was also used as a benchmark for the novel compound (DAPB) in vitro and in vivo experiments.
Application of an assay Cascade methodology for a deep preclinical characterization of polymeric nanoparticles as a treatment for gliomas
Published in Drug Delivery, 2018
Cristina Fornaguera, Miguel Ángel Lázaro, Pau Brugada-Vilà, Irene Porcar, Ingrid Morera, Marta Guerra-Rebollo, Cristina Garrido, Núria Rubio, Jerónimo Blanco, Anna Cascante, Salvador Borrós
Thirteen milligramS of dicyclohexylcarbodiimide (0.064 mmol) and 5 mg of N,N′-dimethylaminopyridine (0.038 mmol) were added to a solution of 100 mg linker (0.032 mmol) in 0.8 mL dry dichloromethane. The reaction mixture was stirred for 1 h at room temperature. Two hundred milligram of Polymer P* in 0.5 mL dry dichloromethane was added to the reaction and stirred at room temperature for 20 h. The solvent was reduced under vacuum and 10 mL diethyl ether were added to the residue. The suspension was centrifuged at 4000 rpm for 10 min and the solvent was removed. Five milliliterS of diethyl ether was added to the solid and after a short vortex agitation, it was centrifuged at 4000 rpm for 10 min. The solvent was removed and the obtained product was dried overnight. Eighty-eight milligramS of Seq12 peptide were added to 242 mg of the above product in 2.1 mL dry dimethylformamide. The reaction was stirred for three days at room temperature and was later added to 10 mL diethyl ether. The suspension was centrifuged at 4000 rpm for 10 min and the solvent was removed. Finally, 5 mL diethyl ether were added to the solid and after a short vortex agitation was centrifuged at 4000 rpm for 10 min. the final product was obtained and was dried overnight.
Estrogen-functionalized liposomes grafted with glutathione-responsive sheddable chotooligosaccharides for the therapy of osteosarcoma
Published in Drug Delivery, 2018
Xuelei Yin, Shuaishuai Feng, Yingying Chi, Jinhu Liu, Kaoxiang Sun, Chuanyou Guo, Zimei Wu
Chitooligosaccharides (MW2-5 kDa and degree of deacetylation of 75%) were purchased by Fengan Bio-Pharmaceutica Co., Ltd. (Zhejiang, China) and DSPE-PEG2000-COOH from Avanti Polar Lipids (Alabaster, AL). Doxorubicin hydrochloride (DOX•HCl, purity 99%), estrone, cholesterol (Chol), glutathione (GSH), 3,3′-dithiodipropionic acid (DTOP), succinic anhydride (SA), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC•HCl), N-hydroxysuccinimide (NHS), 4-dimethylaminopyridine (DMAP) were all obtained from Aladdin (Shanghai, China). N,N′-dicyclohexylcarbodiimide (DCC) was purchased from Sigma-Aldrich (USA). For cell culture studies, MG-63 cells were purchased from BeNa Cell Nanosoft Biotechnology LLC Collection (Beijing, China), and LO2 cells were gifted from Medicine and Pharmacy Research Center, Binzhou Medical University. The chemical agents 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and Hoechst 33342 were obtained from Sigma-Aldrich (USA). Dulbecco’s modified Eagle medium (DMEM), and Roswell Park Memorial Institute (RPMI)-1640 medium were purchased from Thermo Fisher Scientific (Shanghai, China). Fetal bovine serum (FBS) was purchased from Shanghai Biotechnology Co., Ltd. All other chemicals were of analytical reagent grade and used without further purification.
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