Influencing the monophenolase/diphenolase activity ratio in tyrosinase

2013 ◽  
Vol 1834 (3) ◽  
pp. 629-633 ◽  
Author(s):  
Mor Goldfeder ◽  
Margarita Kanteev ◽  
Noam Adir ◽  
Ayelet Fishman
Keyword(s):  
Activity Ratio ◽  
Diphenolase Activity

Directed evolution of tyrosinase for enhanced monophenolase/diphenolase activity ratio

2010 ◽  
Vol 47 (7) ◽  
pp. 372-376 ◽  
Author(s):  
Vered Shuster Ben-Yosef ◽  
Mor Sendovski ◽  
Ayelet Fishman
Keyword(s):  
Directed Evolution ◽  
Activity Ratio ◽  
Diphenolase Activity

A cold-adapted tyrosinase with an abnormally high monophenolase/diphenolase activity ratio originating from the marine archaeon Candidatus Nitrosopumilus koreensis

2016 ◽  
Vol 38 (9) ◽  
pp. 1535-1542 ◽  
Author(s):  
Hyerin Kim ◽  
Young Joo Yeon ◽  
Yoo Rae Choi ◽  
Wooho Song ◽  
Seung Pil Pack ◽  
...  
Keyword(s):  
Activity Ratio ◽  
Cold Adapted ◽  
Diphenolase Activity

scholarly journals Extraneous E-Cadherin Engages the Deterministic Process of Somatic Reprogramming through Modulating STAT3 and Erk1/2 Activity

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 284
Author(s):  
Yu-Hao Liu ◽  
Chien-Chang Chen ◽  
Yi-Jen Hsueh ◽  
Li-Man Hung ◽  
David Hui-Kang Ma ◽  
...  
Keyword(s):  
Stochastic Process ◽  
Molecular Mechanism ◽  
Activity Ratio ◽  
Cell Types ◽  
Deterministic Process ◽  
Modes Of Action ◽  
Molecular Events ◽  
Different Cell Types ◽  
Selection Of ◽  
E Cadherin

Although several modes of reprogramming have been reported in different cell types during iPSC induction, the molecular mechanism regarding the selection of different modes of action is still mostly unknown. The present study examined the molecular events that participate in the selection of such processes at the onset of somatic reprogramming. The activity of STAT3 versus that of Erk1/2 reversibly determines the reprogramming mode entered; a lower activity ratio favors the deterministic process and vice versa. Additionally, extraneous E-cadherin facilitates the early events of somatic reprogramming, potentially by stabilizing the LIF/gp130 and EGFR/ErbB2 complexes to promote entry into the deterministic process. Our current findings demonstrated that manipulating the pSTAT3/pErk1/2 activity ratio in the surrounding milieu can drive different modes of action toward either the deterministic or the stochastic process in the context of OSKM-mediated somatic reprogramming.

scholarly journals Lysyl-tRNA synthetase from Escherichia coli K12. Chromatographic heterogeneity and the lysU-gene product

1987 ◽  
Vol 248 (1) ◽  
pp. 43-51 ◽  
Author(s):  
J Charlier ◽  
R Sanchez
Keyword(s):  
Escherichia Coli ◽  
Gene Product ◽  
Activity Ratio ◽  
Deae Cellulose ◽  
Trna Synthetase ◽  
Trna Synthetases ◽  
E Coli ◽  
Aminoacyl Trna Synthetases

In contrast with most aminoacyl-tRNA synthetases, the lysyl-tRNA synthetase of Escherichia coli is coded for by two genes, the normal lysS gene and the inducible lysU gene. During its purification from E. coli K12, lysyl-tRNA synthetase was monitored by its aminoacylation and adenosine(5′)tetraphospho(5′)adenosine (Ap4A) synthesis activities. Ap4A synthesis was measured by a new assay using DEAE-cellulose filters. The heterogeneity of lysyl-tRNA synthetase (LysRS) was revealed on hydroxyapatite; we focused on the first peak, LysRS1, because of its higher Ap4A/lysyl-tRNA activity ratio at that stage. Additional differences between LysRS1 and LysRS2 (major peak on hydroxyapatite) were collected. LysRS1 was eluted from phosphocellulose in the presence of the substrates, whereas LysRS2 was not. Phosphocellulose chromatography was used to show the increase of LysRS1 in cells submitted to heat shock. Also, the Mg2+ optimum in the Ap4A-synthesis reaction is much higher for LysRS1. LysRS1 showed a higher thermostability, which was specifically enhanced by Zn2+. These results in vivo and in vitro strongly suggest that LysRS1 is the heat-inducible lysU-gene product.

Global fallout levels of 99Tc and activity ratio of 99Tc/137Cs in the Pacific Ocean

2005 ◽  
Vol 266 (3) ◽  
pp. 455-460 ◽  
Author(s):  
N. Momoshima ◽  
M. Sayad ◽  
M. Yamada ◽  
M. Takamura ◽  
H. Kawamura
Keyword(s):  
Pacific Ocean ◽  
Activity Ratio ◽  
Global Fallout ◽  
The Pacific ◽  
The Pacific Ocean

Involvement of cAMP-dependent protein kinase in the regulation of heart contractile force. II

1979 ◽  
Vol 236 (1) ◽  
pp. H84-H91
Author(s):  
S. L. Keely ◽  
A. Eiring
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Activity Ratio ◽  
Contractile Force ◽  
Protein Kinase Activity ◽  
Phosphorylase Activity ◽  
Dependent Protein Kinase ◽  
Guinea Pig Heart ◽  
Camp Dependent Protein Kinase ◽  
Dependent Protein

The effects of histamine on heart cAMP-dependent protein kinase activity, cAMP levels, phosphorylase activity, and contractile force was investigated in the perfused guinea pig heart. To accurately determine the protein kinase activity ratio in guinea pig heart, it was necessary to measure kinase activity in whole homogenates immediately after homogenization of the tissue. Histamine produced a rapid dose-dependent increase in cAMP and the protein kinase activity ratio followed by increased in contractile force and phosphorylase activity. There was a good correlation between the degree of protein kinase activation and the increase in phosphorylase and force. The beta-adrenergic blocking agent propranolol did not reduce the effects of histamine, but metiamide, a potent H2-receptor antagonist, greatly attenuated all the effects of histamine. The data support the hypothesis that increases in heart cAMP-dependent protein kinase activity produce corresponding increases in contractile force and phosphorylase activity.

Growth rate and habitat of Nautilus pompilius inferred from radioactive and stable isotope studies

Paleobiology ◽  
1981 ◽  
Vol 7 (4) ◽  
pp. 469-480 ◽  
Author(s):  
J. Kirk Cochran ◽  
Danny M. Rye ◽  
Neil H. Landman
Keyword(s):  
Growth Rate ◽  
Half Life ◽  
Activity Ratio ◽  
Sea Water ◽  
Tissue Growth ◽  
Carbon And Oxygen Isotopes ◽  
Nautilus Pompilius ◽  
Radioactive Disequilibrium ◽  
Horizontal Migration ◽  
Isotope Studies

The growth rate of Nautilus pompilius in its natural environment has been determined from radioactive disequilibrium between 210Pb (half-life 22.3 yr) and its granddaughter 210Po (half-life 138 d) in septa of two juvenile specimens. 210Pb and 210Po data from the most recently formed shell material of both specimens indicate that 210Pb from sea water is incorporated into septa during septal formation and 210Po is excluded. Therefore the 210Po/210Pb activity ratio serves as a chronometer to estimate the age of each septum and the time between formation of septa. In the specimens studied the average time between sucessive points in septal deposition is 75 d for the nine most recent septa of one specimen and 23 d for the six most recent septa of the other specimen. These different growth rates, if representative of the ontogeny of each animal, suggest that the timing of septal deposition probably is dependent on the rate of shell and tissue growth coupled with buoyancy requirements and is not a unique period for all Nautilus. The habitat and ontogeny of Nautilus may be inferred from the pattern of stable isotopes of oxygen and carbon in the septa. Both specimens show a pronounced break in δ18O from nearly uniform light values in the first seven septa to heavier values (∼1%) after the seventh septum. We interpret this break to correspond to the hatching of Nautilus. A temperature (i.e. water depth) interpretation of the δ18O data for septa after the eighth is complicated by a positive correlation between δ18O and δ13C. This may reflect horizontal migration of the animal or a kinetically controlled fractionation of carbon and oxygen isotopes during septal formation.

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