Measurement of Thermodynamic Parameters for Hydrophobic Mismatch 1:  Self-Association of a Transmembrane Helix†

Biochemistry ◽  
2006 ◽  
Vol 45 (10) ◽  
pp. 3370-3378 ◽  
Author(s):  
Yoshiaki Yano ◽  
Katsumi Matsuzaki
Keyword(s):  
Thermodynamic Parameters ◽  
Transmembrane Helix ◽  
Hydrophobic Mismatch ◽  
Self Association

Thermodynamics of Insertion and Self-Association of a Transmembrane Helix: A Lipophobic Interaction by Phosphatidylethanolamine

Biochemistry ◽  
2011 ◽  
Vol 50 (32) ◽  
pp. 6806-6814 ◽  
Author(s):  
Yoshiaki Yano ◽  
Arisa Yamamoto ◽  
Mai Ogura ◽  
Katsumi Matsuzaki
Keyword(s):  
Transmembrane Helix ◽  
Self Association

Nuclear magnetic resonance studies. X. Determination of the thermodynamic parameters of the self-association of tricyclic aromatic aldehydes in solution

1967 ◽  
Vol 45 (3) ◽  
pp. 213-219 ◽  
Author(s):  
Gurudata ◽  
R. E. Klinck ◽  
J. B. Stothers
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Temperature Dependence ◽  
Thermodynamic Parameters ◽  
Aromatic Aldehydes ◽  
The Self ◽  
Kcal Mole ◽  
Magnetic Resonance Studies ◽  
Self Association

The temperature dependence of the formyl proton shieldings of 9-anthraldehyde and 9-phenanthraldehyde in chloroform solutions has been measured. Four concentrations in the range 0.5–5.0 mole % were examined over the temperature interval − 60 to + 90 °C. From these results, the enthalpies and entropies of formation have been estimated for the complex formed by the self-association of two aldehyde molecules. The calculations indicate the ΔH and ΔS values to be − 1.9 ± 0.3 kcal/mole and − 6 ± 1 e.u., respectively. These results are compared with other available data.

scholarly journals TatA and TatB generate a hydrophobic mismatch that is important for function and assembly of the Tat translocon in Escherichia coli

2021 ◽  
Author(s):  
Denise Mehner-Breitfeld ◽  
Michael T. Ringel ◽  
Daniel Alexander Tichy ◽  
Laura J. Endter ◽  
Kai Steffen Stroh ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Transmembrane Helix ◽  
Length Variation ◽  
Hydrophobic Mismatch ◽  
Hydrophobic Residues ◽  
Transmission Electron ◽  
Absolute Requirement ◽  
Bacterial Model ◽  
Folded Proteins ◽  
Dynamics Simulations

The Tat system translocates folded proteins across energy-transducing prokaryotic membranes. In the bacterial model system Escherichia coli, the three components TatA, TatB, and TatC assemble to functional translocons. TatA and TatB both possess an N-terminal transmembrane helix (TMH) that is followed by an amphipathic helix (APH). The TMHs of TatA and TatB generate a hydrophobic mismatch with only 12 consecutive hydrophobic residues that span the membrane. We shortened or extended this stretch of hydrophobic residues in either TatA, TatB, or both, and analyzed effects on transport functionality and translocon assembly. The wild type length functioned best but was not an absolute requirement, as some variation was tolerated. Length-variation in TatB clearly destabilized TatBC-containing complexes, indicating that the 12-residues-length is crucial for Tat component interactions and translocon assembly. Metal tagging transmission electron microscopy revealed the dimensions of TatA assemblies, which prompted molecular dynamics simulations. These showed that interacting TMHs of larger TatA assemblies can thin the membrane together with laterally aligned tilted APHs that generate a deep V-shaped groove. The conserved hydrophobic mismatch may thus be important for membrane destabilization during Tat transport, and the exact length of 12 hydrophobic residues could be a compromise between functionality and proton leakage minimization.

The self-association of Pyrrolid-2-one in acetonitrile and chloroform: An N.M.R. spectroscopic study

1972 ◽  
Vol 25 (1) ◽  
pp. 67 ◽  
Author(s):  
LF Blackwell ◽  
PD Buckley ◽  
KW Jolley ◽  
ID Watson
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Magnetic Resonance Spectroscopy ◽  
Spectroscopic Study ◽  
Thermodynamic Parameters ◽  
Reasonable Agreement ◽  
The Self ◽  
Resonance Spectroscopy ◽  
Self Association

The self-association of pyrrolid-2-one has been studied in CDCl3 and CD3CN at several temperatures by the use of high resolution nuclear magnetic resonance spectroscopy. The enthalpies of self-association of the lactam in the two solvents have been measured and are in reasonable agreement with those for similar systems determined by the use of other methods. The enthalpy of salvation of pyrrolid-2-one in CHCl3 has also been measured. A discussion on the validity of the approximations used in the calculations of the thermodynamic parameters has been included.

Topological Stability and Self-Association of a Completely Hydrophobic Model Transmembrane Helix in Lipid Bilayers†

Biochemistry ◽  
2002 ◽  
Vol 41 (9) ◽  
pp. 3073-3080 ◽  
Author(s):  
Yoshiaki Yano ◽  
Tomokazu Takemoto ◽  
Satoe Kobayashi ◽  
Hiroyuki Yasui ◽  
Hiromu Sakurai ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Transmembrane Helix ◽  
Topological Stability ◽  
Self Association
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