C-terminal hybrid mutant of Bacillus pumilus cyanide dihydratase dramatically enhances thermal stability and pH tolerance by reinforcing oligomerization

2015 ◽  
Vol 118 (4) ◽  
pp. 881-889 ◽  
Author(s):  
M.A. Crum ◽  
J.M. Park ◽  
B.T. Sewell ◽  
M.J. Benedik
Keyword(s):  
Thermal Stability ◽  
Bacillus Pumilus ◽  
Ph Tolerance ◽  
Cyanide Dihydratase

scholarly journals Isolation and characterization of a cyanide dihydratase from Bacillus pumilus C1.

1993 ◽  
Vol 175 (19) ◽  
pp. 6105-6112 ◽  
Author(s):  
P R Meyers ◽  
D E Rawlings ◽  
D R Woods ◽  
G G Lindsey
Keyword(s):  
Bacillus Pumilus ◽  
Isolation And Characterization ◽  
Cyanide Dihydratase

scholarly journals CynD, the Cyanide Dihydratase from Bacillus pumilus: Gene Cloning and Structural Studies

2003 ◽  
Vol 69 (8) ◽  
pp. 4794-4805 ◽  
Author(s):  
Dakshina Jandhyala ◽  
Mark Berman ◽  
Paul R. Meyers ◽  
B. Trevor Sewell ◽  
Richard C. Willson ◽  
...  
Keyword(s):  
Bacillus Pumilus ◽  
Spiral Structure ◽  
Sequence Similarity ◽  
Affinity Purification ◽  
Three Dimensional ◽  
Pseudomonas Stutzeri ◽  
Recombinant Enzyme ◽  
Dimensional Reconstruction ◽  
Short Spiral ◽  
Cyanide Dihydratase

ABSTRACT The cyanide dihydratase in Bacillus pumilus was shown to be an 18-subunit spiral structure by three-dimensional reconstruction of electron micrographs of negatively stained material at its optimum pH, 8.0. At pH 5.4, the subunits rearrange to form an extended left-handed helix. Gel electrophoresis of glutaraldehyde cross-linked enzyme suggests that the fundamental component of the spiral is a dimer of the 37-kDa subunit. The gene was cloned, and the recombinant enzyme was readily expressed at high levels in Escherichia coli. Purification of the recombinant enzyme was facilitated by the addition of a C-terminal six-histidine affinity purification tag. The tagged recombinant enzyme has Km and V max values similar to those published for the native enzyme. This is the first cyanide dihydratase from a gram-positive bacterium to be sequenced, and it is the first description of the structure of any member of this enzyme class. The putative amino acid sequence shares over 80% identity to the only other sequenced cyanide dihydratase, that of the gram-negative Pseudomonas stutzeri strain AK61, and is similar to a number of other bacterial and fungal nitrilases. This sequence similarity suggests that the novel short spiral structure may be typical of these enzymes. In addition, an active cyanide dihydratase from a non-cyanide-degrading isolate of B. pumilus (strain 8A3) was cloned and expressed. This suggests that cynD, the gene coding for the cyanide dihydratase, is not unique to the C1 strain of B. pumilus and is not a reflection of its origin at a mining waste site.

scholarly journals The structure of the cyanide dihydratase (CynD) from Bacillus pumilus

2017 ◽  
Vol 73 (a2) ◽  
pp. C1296-C1296
Author(s):  
Bryan Trevor Sewell ◽  
Achilleas Frangakis ◽  
Andani Mulelu ◽  
Julian Reitz
Keyword(s):  
Bacillus Pumilus ◽  
Cyanide Dihydratase

Residue Y70 of the Nitrilase Cyanide Dihydratase from Bacillus pumilus Is Critical for Formation and Activity of the Spiral Oligomer

2016 ◽  
Vol 26 (12) ◽  
pp. 2179-2183
Author(s):  
Jason M. Park ◽  
Christian M. Ponder ◽  
B. Trevor Sewell ◽  
Michael J. Benedik
Keyword(s):  
Bacillus Pumilus ◽  
Cyanide Dihydratase

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

Microstructure studies of tungsten silicide schottky contacts on Gaas

1987 ◽  
Vol 45 ◽  
pp. 328-329
Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie
Keyword(s):  
Thermal Stability ◽  
Field Effect Transistors ◽  
Schottky Contact ◽  
Schottky Contacts ◽  
Excellent Thermal Stability ◽  
Barrier Heights ◽  
Gaas Substrates ◽  
Film Adhesion ◽  
Threshold Voltages ◽  
Thermal Stability Of

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.

Evolution of the microstructure of Cu(Ti)/SiO2 layers annealed in NH3

1995 ◽  
Vol 53 ◽  
pp. 452-453
Author(s):  
J. Liu ◽  
N. D. Theodore ◽  
D. Adams ◽  
S. Russell ◽  
T. L. Alford ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Titanium Nitride ◽  
Large Scale ◽  
Standard Procedure ◽  
Alloy Film ◽  
Electron Beam Evaporation ◽  
Copper Metallization ◽  
Nominal Composition ◽  
Ti Alloy ◽  
Thermally Grown

Copper-based metallization has recently attracted extensive research because of its potential application in ultra-large-scale integration (ULSI) of semiconductor devices. The feasibility of copper metallization is, however, limited due to its thermal stability issues. In order to utilize copper in metallization systems diffusion barriers such as titanium nitride and other refractory materials, have been employed to enhance the thermal stability of copper. Titanium nitride layers can be formed by annealing Cu(Ti) alloy film evaporated on thermally grown SiO2 substrates in an ammonia ambient. We report here the microstructural evolution of Cu(Ti)/SiO2 layers during annealing in NH3 flowing ambient.The Cu(Ti) films used in this experiment were prepared by electron beam evaporation onto thermally grown SiO2 substrates. The nominal composition of the Cu(Ti) alloy was Cu73Ti27. Thermal treatments were conducted in NH3 flowing ambient for 30 minutes at temperatures ranging from 450°C to 650°C. Cross-section TEM specimens were prepared by the standard procedure.

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