Differential cytochrome content and reductase activity in Geospirillum barnesii strain SeS3

1997 ◽  
Vol 167 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. F. Stolz ◽  
Theresa Gugliuzza ◽  
Jodi Switzer Blum ◽  
Ronald Oremland ◽  
Francisco Martínez Murillo
Keyword(s):  
Reductase Activity ◽  
Cytochrome Content

Cytochrome content in Azospirillum brasilense Sp 7 grown under aerobic and denitrifying conditions

1987 ◽  
Vol 33 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Roger Lalande ◽  
Roger Knowles
Keyword(s):  
Electron Acceptor ◽  
Azospirillum Brasilense ◽  
Nitrate Reductase Activity ◽  
Soluble Fraction ◽  
Reductase Activity ◽  
Batch Cultures ◽  
Final Electron ◽  
Cytochrome Content ◽  
Soluble C ◽  
Final Electron Acceptor

Azospirillum brasilense Sp 7 was grown in batch cultures with O2, [Formula: see text], [Formula: see text], or N2O as final electron acceptor. There were marked differences in cytochrome composition depending on the O2 status of the culture and the electron acceptor utilized. Highly aerated cultures showed no [Formula: see text] reduction and the cytochrome composition (a soluble c-type and particulate aa3, b, and c cytochromes) was not affected by the presence of[Formula: see text]. Under low aeration, in the presence of [Formula: see text], nitrate reductase activity occurred and there was a significant increase in the soluble and particulate cytochromes. Particulate cytochrome b-556 was observed only under high aeration and the cytochrome aa3, observed under both high and low aeration, decreased as the O2 concentration decreased. A particulate CO-binding cytochrome of type o was observed in the cells grown under high aeration. Cytochrome cd nitrite reductase was observed only in the soluble fraction of [Formula: see text]-grown cultures, which also contained the highest concentrations of the soluble cytochrome c-548 and the particulate c-551. N2O-grown cultures showed b-560 and c-551 cytochromes in the particulate and the c-548 cytochrome in the soluble fraction.

Lamin B receptor: role on chromatin structure, cellular senescence and possibly aging

2020 ◽  
Vol 477 (14) ◽  
pp. 2715-2720
Author(s):  
Susana Castro-Obregón
Keyword(s):  
Cellular Senescence ◽  
Nuclear Membrane ◽  
Chromatin Structure ◽  
Cholesterol Synthesis ◽  
Reductase Activity ◽  
Chimeric Protein ◽  
Nuclear Lamina ◽  
Lamin B ◽  
Inner Nuclear Membrane ◽  
Lamin B Receptor

The nuclear envelope is composed by an outer nuclear membrane and an inner nuclear membrane, which is underlain by the nuclear lamina that provides the nucleus with mechanical strength for maintaining structure and regulates chromatin organization for modulating gene expression and silencing. A layer of heterochromatin is beneath the nuclear lamina, attached by inner nuclear membrane integral proteins such as Lamin B receptor (LBR). LBR is a chimeric protein, having also a sterol reductase activity with which it contributes to cholesterol synthesis. Lukasova et al. showed that when DNA is damaged by ɣ-radiation in cancer cells, LBR is lost causing chromatin structure changes and promoting cellular senescence. Cellular senescence is characterized by terminal cell cycle arrest and the expression and secretion of various growth factors, cytokines, metalloproteinases, etc., collectively known as senescence-associated secretory phenotype (SASP) that cause chronic inflammation and tumor progression when they persist in the tissue. Therefore, it is fundamental to understand the molecular basis for senescence establishment, maintenance and the regulation of SASP. The work of Lukasova et al. contributed to our understanding of cellular senescence establishment and provided the basis that lead to the further discovery that chromatin changes caused by LBR reduction induce an up-regulated expression of SASP factors. LBR dysfunction has relevance in several diseases and possibly in physiological aging. The potential bifunctional role of LBR on cellular senescence establishment, namely its role in chromatin structure together with its enzymatic activity contributing to cholesterol synthesis, provide a new target to develop potential anti-aging therapies.

Visceral fat drives 5[alpha]-reductase activity independent of BMI in women with polycystic ovarian syndrome

2015 ◽  
Author(s):  
Punith Kempegowda ◽  
Michael W O'Reilly ◽  
Nicola J Crabtree ◽  
Angela E Taylor ◽  
Beverly A Hughes ◽  
...  
Keyword(s):  
Visceral Fat ◽  
Polycystic Ovarian Syndrome ◽  
Reductase Activity ◽  
Ovarian Syndrome

Nitrate Reductase Activity of Maize Hybrids and Their Parental Inbred 1

Crop Science ◽  
1966 ◽  
Vol 6 (2) ◽  
pp. 169-173 ◽  
Author(s):  
L. E. Schrader ◽  
D. M. Peterson ◽  
E. R. Leng ◽  
R. H. Hageman
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Reductase Activity ◽  
Maize Hybrids ◽  
Parental Inbred
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