Novel Cytochrome P450 Bioactivation of a Terminal Phenyl Acetylene Group: Formation of a One-Carbon Loss Benzaldehyde and Other Oxidative Products in the Presence ofN-Acetyl Cysteine or Glutathione

To study the role of sulfhydryl group formation during cell cycle progression, mammalian tissue culture cells (PTK2) were exposed to 100¼M 2-mercaptoethanol for 2 to 6 h during their exponential phase of growth. The effects of 2-mercaptoethanol on centrosomes, chromosomes, microtubules, membranes and intermediate filaments were analyzed by transmission electron microscopy (TEM) and by immunofluorescence microscopy (IFM) methods using a human autoimmune antibody directed against centrosomes (SPJ), and a mouse monoclonal antibody directed against tubulin (E7). Chromosomes were affected most by this treatment: premature chromosome condensation was detected in interphase nuclei, and the structure in mitotic chromosomes was altered compared to control cells. This would support previous findings in dividing sea urchin cells in which chromosomes are arrested at metaphase while the centrosome splitting cycle continues. It might also support findings that certairt-sulfhydryl-blocking agents block cyclin destruction. The organization of the microtubule network was scattered probably due to a looser organization of centrosomal material at the interphase centers and at the mitotic poles.

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Electron microscopy and diffraction of crystalline dendrimers and macrocycles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151921 ◽

1993 ◽

Vol 51 ◽

pp. 1218-1219

Author(s):

C. J. Buchko ◽

P. M. Wilson ◽

Z. Xu ◽

J. Zhang ◽

S. Lee ◽

...

Keyword(s):

Electron Microscopy ◽

Liquid Crystalline ◽

Structural Information ◽

High Resolution Electron Microscopy ◽

Scanning Calorimetry ◽

Tertiary Butyl ◽

Phenyl Acetylene ◽

Selected Area Electron Diffraction ◽

Liquid Crystalline Phases ◽

Resolution Electron

The synthesis of well-defined organic molecules with unique geometries opens new opportunities for understanding and controlling the organization of condensed matter. Here, we study dendrimers and macrocycles which are synthesized from rigid phenyl-acetylene spacer units, Both units are solubilized by the presence of tertiary butyl groups located at the periphery of the molecule. These hydrocarbon materials form crystalline and liquid crystalline phases which have been studied by differential scanning calorimetry, hot stage optical microscopy, and wide-angle x-ray scattering (WAXS).The precisely defined architecture of these molecules makes it possible to investigate systematic variations in chemical architecture on the nature of microstructural organization. Here we report on the transmission electron microscopy (TEM), selected area electron diffraction (SAED), and high resolution electron microscopy (HREM) studies of crystalline thin films formed by deposition of these materials onto carbon substrates from dilute solution. Electron microscopy is very attractive for gaining structural information on new molecules due to the scarcity of material to grow single crystals suitable for conventional crystallography.

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Molecular evolution of a cytochrome P450 for the synthesis of potential antidepressant (2R,6R)-hydroxynorketamine

Chemical Communications ◽

10.1039/d0cc06729f ◽

2021 ◽

Author(s):

Ansgar Bokel ◽

Michael C. Hutter ◽

Vlada B. Urlacher

Keyword(s):

Cytochrome P450 ◽

Molecular Evolution ◽

Cytochrome P450 Monooxygenase ◽

P450 Monooxygenase ◽

Effective Synthesis

Engineered cytochrome P450 monooxygenase CYP154E1 enables the effective synthesis of the potential antidepressant (2R,6R)-hydroxynorketamine via N-demethylation and regio- and stereoselective hydroxylation of (R)-ketamine.

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