Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P39060 (endostatin)
 2,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endostatin can specifically inhibit endothelial proliferation and potently inhibit angiogenesis and tumor growth. N-Terminal site-specific mono-PEGylation of recombinant human endostatin (mPEG-rhES) was accomplished by using methoxy poly-ethylene glycol (mPEG) propionaldehyde with an average molecular weight of 5000 Da through a reactive terminal aldehyde group. The site-specific mPEG conjugation was conducted under optimal conditions, which were identified through a statistical L(9)(3(4)) orthogonal test. In this study, we have investigated the stability and antitumor activity of mPEG-rhES. SDS-PAGE, RP-HPLC, and UV spectrophotometric analysis were used to identify the purity and stability of mPEG-rhES. When incubated with protease or placed in an extreme environment, mPEG-rhES was more stable than rhES. The unmodified and PEGylated rhES were tested for their ability to inhibit the tumor growth of mouse H22 liver cancer in male mice. In a multiple versus single doses comparison study, daily administration of 0.25, 0.50, and 1.00 micromol/kg of unmodified rhES for 7 days resulted in 26.9%, 43.0%, and 64.9% reductions in tumor weight, respectively, while single doses of 0.13, 0.25, and 0.50 micromol/kg of the PEGylated protein per day resulted in 24.8%, 38.0%, and 64.5% reductions, respectively. Both treatments resulted in statistically significant reductions in mean tumor weight as compared to the physiological saline solution (control)-treated mice, with the dose of mPEG-rhES being a half of rhES, respectively, while the tumor inhibition rates were similar. Therefore, it is suggested that PEGylation enhances the stability of rhES and improves its antitumor activity.
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PMID:Preparation and stability of N-terminal mono-PEGylated recombinant human endostatin. 1684 7

In this study, we investigated the PEG attachment site of mono-PEGylated Endostar, a modified recombinant human endostatin approved in China for lung cancer. N-terminal site-directed mono-PEGylation of Endostar was accomplished using mPEG-propionaldehyde derivatives (Mw=20 kDa) under slightly acidic pH conditions (pH 5.5). One-step cation exchange chromatography was used to purify the mono-PEGylated Endostar. Following tryptic digestion, the peptide fragment containing PEG was separated by SDS-PAGE. Barium iodide staining and Western blotting were used to detect the PEG moiety and the N-terminus of Endostar, respectively. The peptide fragment stained by barium iodide showed a positive response to anti-(His) 6 mAb, demonstrating that PEG was located at the N-terminus of Endostar. LC/MS was applied to verify the occurrence of mono-PEGylation at the N-terminus of Endostar.
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PMID:Characterization of a monoPEG20000-Endostar. 2012 57

We have used a novel photochemical Knudsen cell reactor to investigate the uptake and phototransformation of some atmospherically important trace organics on TiO(2) and TiO(2)-SiO(2) mixed films. Illumination of TiO(2) films led to an enhanced uptake of isopropanol and n-propanol and the concurrent production of gas-phase acetone and propionaldehyde, respectively, with high efficiency. Acetone production from isopropanol on illuminated TiO(2) films displayed a significant enhancement in the presence of cosorbed AgNO(3) or KNO(3). Uptake of cyclohexene by TiO(2) films required the presence of both nitrate anion and light. The wavelength and substrate (TiO(2) vs SiO(2)) dependence of the nitrate-induced enhancement in uptake indicates that it was not caused by direct photolysis of nitrate anion. We propose a 2-fold role for nitrate anion in the present experiments: first, as an electron trapping agent that activates the TiO(2) surface toward photooxidation; second, as suggested by our results for cyclohexene, as a source of reactive nitrate radical at the TiO(2) surface. These observations suggest that mineral dust containing photoactive components may catalyze the transformation of photochemically inactive organic compounds into species that absorb in the actinic region.
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PMID:Photooxidation of atmospheric alcohols on laboratory proxies for mineral dust. 2201 74