Calorimetric investigations of association in ternary systems. Part 4.—The influence of solvation on enthalpy of complex formation in phenol-tetrahydrofuran and 2,6-dimethylphenol–tetrahydrofuran systems

1987 ◽  
Vol 83 (9) ◽  
pp. 3083 ◽  
Author(s):  
Pawel Góralski ◽  
Mariola Tkaczyk
Keyword(s):  
Complex Formation ◽  
Ternary Systems ◽  
Enthalpy Of Complex Formation ◽  
Calorimetric Investigations

scholarly journals Role of Secondary Structure in Discrimination between Constitutive and Inducible Activators

1999 ◽  
Vol 19 (8) ◽  
pp. 5601-5607 ◽  
Author(s):  
David Parker ◽  
Morris Rivera ◽  
Tsaffir Zor ◽  
Alexandra Henrion-Caude ◽  
Ishwar Radhakrishnan ◽  
...  
Keyword(s):  
Complex Formation ◽  
Structural Characteristics ◽  
Gene Activation ◽  
Random Coil ◽  
Creb Binding Protein ◽  
Hydrophobic Residues ◽  
Enthalpy Of Complex Formation ◽  
Kix Domain ◽  
Thermodynamics Of Formation

ABSTRACT We have examined structural differences between the proto-oncogene c-Myb and the cyclic AMP-responsive factor CREB that underlie their constitutive or signal-dependent activation properties. Both proteins stimulate gene expression via activating regions that articulate with a shallow hydrophobic groove in the KIX domain of the coactivator CREB-binding protein (CBP). Three hydrophobic residues in c-Myb that are conserved in CREB function importantly in cellular gene activation and in complex formation with KIX. These hydrophobic residues are assembled on one face of an amphipathic helix in both proteins, and mutations that disrupt c-Myb or CREB helicity in this region block interaction of either factor with KIX. Binding of the helical c-Myb domain to KIX is accompanied by a substantial increase in entropy that compensates for the comparatively low enthalpy of complex formation. By contrast, binding of CREB to KIX entails a large entropy cost due to a random coil-to-helix transition in CREB that accompanies complex formation. These results indicate that the constitutive and inducible activation properties of c-Myb and CREB reflect secondary structural characteristics of their corresponding activating regions that influence the thermodynamics of formation of a complex with CBP.

Complex formation in the ternary systems: copper(II)-glycylsarcosine-amino acids

1980 ◽  
Vol 46 ◽  
pp. L17-L19 ◽  
Author(s):  
B.R. Arbad ◽  
D.N. Shelke ◽  
D.V. Jahagirdar
Keyword(s):  
Amino Acids ◽  
Complex Formation ◽  
Ternary Systems
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