PEGylated Dendritic Nanoparticulate Carriers of Anti-Cancer Drugs
Mansoor M. Amiji in Nanotechnology for Cancer Therapy, 2006
Photosensitizers play a crucial role in the photodynamic therapy (PDT) of cancer. Zhang et al. (2003) observed that the use of PIC micelles as a delivery system reduced the dark toxicity of the cationic dendrimer porphyrin, probably because of the biocompatible PEG shell of the micelles. They compared relatively low cellular uptake of dendrimer porphyrin [NH2CH2CH2NHCO]32-DPZn incorporated in the PIC micelle as was observed, yet the latter exhibited enhanced photodynamic efficacy on the Lewis Lung Carcinoma (LLC) cell line. In this study, a third-generation aryl ether dendrimer porphyrin with 32 primary amine groups on the periphery, [NH2CH2CH2NHCO]32DPZn, and pH-sensitive, polyion complex micelles (PIC) composed of the porphyrin dendrimer and PEG-b-poly(aspartic acid) were evaluated as new photosensitizers (PSs) for PDT in the LLC cell line. The preliminary photophysical characteristics of [NH2CH2-CH2NHCO]32DPZn and the corresponding micelles were investigated. Electrostatic assembly resulted in a red-shift of the Soret peak of the porphyrin core and the enhanced fluorescence.
Introduction to Human Cytochrome P450 Superfamily
Shufeng Zhou in Cytochrome P450 2D6, 2018
The cytochrome P450s (CYPs), a large diverse heme-containing enzyme superfamily with a large number of members, are found across all organisms in prokaryotic and eukaryotic worlds from animals, plants, fungi, protists, bacteria, and archaea to viruses (Bolwell et al. 1994; Danielson 2002; Feyereisen 1999; Gillam and Hayes 2013; Kelly and Kelly 2013; Munro and Lindsay 1996; Podust and Sherman 2012; Roberts 1999; Werck-Reichhart and Feyereisen 2000). These proteins were first discovered in 1958 by their unusual reduced carbon monoxide difference spectrum that exhibits a Soret peak at 450 nm, thus called “Pigment at 450 nm” or “P450” (Omura and Sato 1964). The unique spectral peak is produced by a thiolate anion acting as the fifth ligand to the heme. This peak is a unique feature only observed in four classes of hemoproteins, namely, P450s, nitric oxide synthases, chloroperoxidases, and protein H450 (Omura 2005; Poulos 2014; van Rantwijk and Sheldon 2000). The nomenclature of CYPs is based on the protein sequences, with similar sequences being clustered into families and subfamilies. CYP genes form a multigene family and encode proteins with amino acid sequence identities >40%. Each family comprises subfamilies with amino acid sequence identities >55%. In the classification of CYPs, a clan is defined as a higher-order category of CYP families. To date, the CYP genes from all organisms consist of at least 700 families and 800 subfamilies.
Impact of single nucleotide polymorphisms (R132Q and W120R) on the binding affinity and metabolic activity of CYP2C19 toward some therapeutically important substrates
Published in Xenobiotica, 2020
Sayed M. Derayea, Hirofumi Tsujino, Yukiko Oyama, Yoshinobu Ishikawa, Taku Yamashita, Tadayuki Uno
Amitriptyline, lansoprazole, cytochrome P450 reductase and cytochrome b5 were purchased from Sigma-Aldrich (St. Louis, MO). Imipramine, omeprazole and other chemicals were purchased from Wako Pure Chemical Industries, Ltd. (Osaka, Japan). CYP2C19 was expressed using an over-expression system in E. coli and purified by column chromatography as previously reported (Attia et al., 2012). The purity of the prepared proteins was confirmed by using SDS-PAGE and UV-spectrophotometry. To ensure purity, the absorbance at 280 nm must be about one half of that at 417.5 nm, as well as, the Soret peak of the CO-bound ferrous form should be located at 450 nm. The stock solutions of all drugs were prepared in 100 mM potassium phosphate buffer containing 20% glycerol, while in the case of UV and Raman spectroscopy measurements, lansoprazole and omeprazole were dissolved in the least volume of dimethyl sulfoxide (DMSO). NADPH generating solution (containing 1 mM β-NADP+, 2.5 mM G6P and 2 U/mL G6PDH) was purchased from Oriental Yeast Co., Ltd. (Tokyo, Japan), and was constituted in 100 mM potassium phosphate buffer (KPi buffer, pH 7.4) with 2.5 mM MgCl2. Mutations in CYP2C19 gene were introduced through using the QuikChange (Stratagene, San Diego, CA) site-directed mutagenesis kit and the mutated sequences were confirmed by DNA sequencing.
Improved oxygen storage capacity of haemoglobin submicron particles by one-pot formulation
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Chiraphat Kloypan, Ausanai Prapan, Nittiya Suwannasom, Saranya Chaiwaree, Waraporn Kaewprayoon, Axel Steffen, Yu Xiong, Nuttakorn Baisaeng, Radostina Georgieva, Hans Bäumler
In terms of protein functionality, the UV-VIS spectrophotometric analysis in Figure 6 exhibited the ability of Odex-HbMP to bind and release oxygen in comparison with stroma-free Hb. Oxygenated Odex-HbMP demonstrated three absorption peaks at 414, 542 and 576 nm, which correspond to the oxygenated Hb (OxyHb). After deoxygenation of the Odex-HbMP using 1 mg/mL sodium dithionite (SDT), a red shift of the 414 nm peak (the Soret peak) to 432 nm was observed. A peak at 556 nm was detected instead while the peaks at 542 and 576 nm disappeared. The absorption spectra of Odex-HbMP showed the characteristic shape of oxygenated/deoxygenated Hb and confirmed the functionality of Odex-HbMP. The shift to higher absorption values of Odex-HbMP spectra compared to the Hb solution is due to the scattering of Odex-HbMP.
Pharmacophore-based discovery of 2-(phenylamino)aceto-hydrazides as potent eosinophil peroxidase (EPO) inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2018
Daniela Schuster, Martina Zederbauer, Thierry Langer, Andreas Kubin, Paul G. Furtmüller
Firstly we investigated compound 10. EPO Compound I can be formed with equimolar concentrations hydrogen peroxide. Compound I decays within the first 10 s to a ferryl/protein radical species32. However, in the presence of a compound 10 this reaction is negligible. Figure 4(A) shows the spectral transition when preformed EPO Compound I (2 µM) was mixed with 10 µM compound 10 at pH 7.0 and 25 °C. A very fast direct transition of Compound I (black spectrum) to Compound II (orange spectrum) can be seen, followed by a slow transition to Compound III (green spectrum) with spectral signature (Soret peak at 423 nm and two bands in the visible range at 552 and 588 nm) similar to LPO Compound III33. Compound I reduction with compound 10 was measured at 423 nm. At this wavelength both the Compound II formation and the transition to Compound III could be followed.
Related Knowledge Centers
- Absorption Spectroscopy
- Carbon Monoxide
- Enzyme
- Heme
- Porphyrin
- Spectroscopy
- Cytochrome P450
- Visible Spectrum
- Moiety
- Monooxygenase