Structural determinant for cold inactivation of rodent l-xylulose reductase

2003 ◽  
Vol 308 (1) ◽  
pp. 68-72 ◽  
Author(s):  
Shuhei Ishikura ◽  
Noriyuki Usami ◽  
Ossama El-Kabbani ◽  
Akira Hara
Biochemistry ◽  
1997 ◽  
Vol 36 (26) ◽  
pp. 7967-7972 ◽  
Author(s):  
Christian S. Hamann ◽  
Ya-Ming Hou

Author(s):  
Andrew Milner ◽  
J.R. Burgmann

The chapter opens with a discussion of two early instances of global warming cli-fi, Arthur Herzog’s Heat and George Turner’s The Sea and Summer, and argues that both are more or less oblivious to the wider world beyond their respective national frontiers. It proceeds to elaborate an account of the place of SF in the world literary system, understood in Wallerstein and Moretti’s terms as comprising a core, semi-periphery and periphery. This model is then applied more specifically to cli-fi, distinguishing between structural and conjunctural determinants of the evolution of the sub-genre. The main structural determinant, it argues, will be the world SF system. But this may be either countered or reinforced by one or more of three main conjunctural factors: the degree of perceived vulnerability to extreme climate change of any particular national political economy; the salience of Green politics within any particular national polity; and the salience of climate change within broader environmentalist discussions in any particular national culture. The chapter concludes with critical accounts of Kim Stanley Robinson’s Science in the Capital trilogy, Frank Schätzing’s Der Schwarm, Margaret Atwood’s MaddAddam trilogy and Antti Tuomainen’s Parantaja.


1990 ◽  
Vol 45 (1-2) ◽  
pp. 42-46 ◽  
Author(s):  
Leszek A. Kleczkowski ◽  
Gerald E. Edwards

Abstract Maize (Zea mays L.) leaf phosphoenolpyruvate (PEP) carboxylase (PEPCase) (EC 4.1.1.31) showed a lag in activity when assayed after storage at 0-4 °C. The lag was promoted by high pH on storage (7.8 -8.5) and was observed over a range of assay pH (7.1 -8.5). Thermal reacti­vation of the cold-stored enzyme by assay temperature (18 °C) accounted for most of the hysteretic effect, but presence of PEP in the reaction mixture was required to completely eliminate the lag. Based on steady-state rates after the lag, stability of PEPCase in the cold was inde­pendent of protein concentration . It is suggested that low temperature and high pH induce a change in the oligomerization state of PEPCase, resulting in a less active but relatively stable form of the enzyme. The lag probably reflects a reversal of this process, promoted by assay temperature and presence of PEP.


Structure ◽  
2020 ◽  
Vol 28 (7) ◽  
pp. 847-857.e5
Author(s):  
Yael Ben-Nun ◽  
Hyuk-Soo Seo ◽  
Edward P. Harvey ◽  
Zachary J. Hauseman ◽  
Thomas E. Wales ◽  
...  

2015 ◽  
Vol 35 (10) ◽  
pp. 1727-1740 ◽  
Author(s):  
Jianli Gong ◽  
Yongneng Yao ◽  
Pingbo Zhang ◽  
Barath Udayasuryan ◽  
Elena V. Komissarova ◽  
...  

The diverse roles of protein kinase C-δ (PKCδ) in cellular growth, survival, and injury have been attributed to stimulus-specific differences in PKCδ signaling responses. PKCδ exerts membrane-delimited actions in cells activated by agonists that stimulate phosphoinositide hydrolysis. PKCδ is released from membranes as a Tyr313-phosphorylated enzyme that displays a high level of lipid-independent activity and altered substrate specificity during oxidative stress. This study identifies an interaction between PKCδ's Tyr313-phosphorylated hinge region and its phosphotyrosine-binding C2 domain that controls PKCδ's enzymology indirectly by decreasing phosphorylation in the kinase domain ATP-positioning loop at Ser359. We show that wild-type (WT) PKCδ displays a strong preference for substrates with serine as the phosphoacceptor residue at the active site when it harbors phosphomimetic or bulky substitutions at Ser359.In contrast, PKCδ-S359A displays lipid-independent activity toward substrates with either a serine or threonine as the phosphoacceptor residue. Additional studies in cardiomyocytes show that oxidative stress decreases Ser359phosphorylation on native PKCδ and that PKCδ-S359A overexpression increases basal levels of phosphorylation on substrates with both phosphoacceptor site serine and threonine residues. Collectively, these studies identify a C2 domain-pTyr313docking interaction that controls ATP-positioning loop phosphorylation as a novel, dynamically regulated, and physiologically relevant structural determinant of PKCδ catalytic activity.


2018 ◽  
Vol 59 (10) ◽  
pp. 1871-1879 ◽  
Author(s):  
Diego E. Sastre ◽  
Emilio Saita ◽  
Antonio D. Uttaro ◽  
Diego de Mendoza ◽  
Silvia G. Altabe

1989 ◽  
Vol 44 (8) ◽  
pp. 955-958 ◽  
Author(s):  
George Dreyfus ◽  
Leopoldo de Meis

Mitochondrial F1 ATPase is inactivated by urea. Protection against urea inactivation is obtained when betaine, a methylamine found in different tissues, is added to the assay medium. Protection is also obtained upon the addition of either glycerol or dimethyl sulfoxide to the assay medium. The F, ATPase is rapidly inactivated at 4 °C. Inactivation by low temperature is prevented by betaine, glycerol and dimethyl sulfoxide. The protective effect of organic solvents and betaine against cold inactivation is prevented by urea.


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