New insights on the effect of the hydrolysing agents in the synthesis of pristine fibrous silica zeolite X for enhancement of side chain methylation of toluene: Theoretical and experimental studies

Fuel ◽  
2022 ◽  
Vol 315 ◽  
pp. 123232
Author(s):  
M.A.H. Aziz ◽  
A.A. Jalil ◽  
I. Hussain ◽  
S.M. Izan ◽  
S.A. Setu ◽  
...  
2016 ◽  
Vol 234 ◽  
pp. 61-72 ◽  
Author(s):  
He Han ◽  
Min Liu ◽  
Xiaowa Nie ◽  
Fanshu Ding ◽  
Yiren Wang ◽  
...  

2016 ◽  
Vol 55 (7) ◽  
pp. 1849-1858 ◽  
Author(s):  
He Han ◽  
Min Liu ◽  
Fanshu Ding ◽  
Yiren Wang ◽  
Xinwen Guo ◽  
...  

Fuel ◽  
2021 ◽  
Vol 305 ◽  
pp. 121432
Author(s):  
M.A.H Aziz ◽  
A.A Jalil ◽  
T.J Siang ◽  
I. Hussain ◽  
A.F.A Rahman ◽  
...  

2016 ◽  
Vol 424 ◽  
pp. 98-105 ◽  
Author(s):  
Hideshi Hattori ◽  
Abdulhameed A. Amusa ◽  
Rabindran B. Jermy ◽  
Abdullah M. Aitani ◽  
Sulaiman S. Al-Khattaf
Keyword(s):  

2020 ◽  
Author(s):  
Soumendranath Bhakat ◽  
Pär Söderhjelm

AbstractFlexibility of β hairpin structure known as flap plays a key role in catalytic activity and substrate intake in pepsin-like aspartic proteases. Most of these enzymes share structural and sequence similarity. Tyrosine is a conserved residue present in the flap region of pepsin-like aspartic proteases. In apo protease, tyrosine remains in a dynamic equilibrium between normal and flipped states due to rotation of χ1 angle (distributions of the χ1 angle centred around radian or radian are denoted as normal, whereas distribution centred around ±π radian is denoted as flipped). In this study, we have used apo Plm-II and BACE-1 as model systems. Independent MD simulations starting with Plm-II and BACE-1 remained stuck either in normal or flipped state. Metadynamics simulations using torsion angles (χ1 and χ2 of Tyr) as CVs sampled transition between normal and flipped states. Qualitatively, flipped and normal states predicted to be equally populated. These states were stabilised by H-bond interactions to tryptophan (normal) and catalytic aspartate (flipped) respectively. Further, mutation of tyrosine to an amino-acid with smaller side-chain, such as alanine; reduced flap flexibility and resulted in a flap collapse. This is in accordance with previous experimental studies which showed that mutation to alanine resulted in loss of activity in pepsin-like aspartic proteases. Using apo plasmepsin-II and BACE-1 as model systems, we have hypothesised that the rotation of tyrosine side-chain is the key movement which governs the flap dynamics in all pepsin-like aspartic proteases.


2012 ◽  
Vol 443-444 ◽  
pp. 214-220 ◽  
Author(s):  
Balkrishna B. Tope ◽  
Wahab O. Alabi ◽  
Abdullah M. Aitani ◽  
Hideshi Hattori ◽  
Sulaiman S. Al-Khattaf
Keyword(s):  

2013 ◽  
Vol 143 (10) ◽  
pp. 1025-1029 ◽  
Author(s):  
Hideshi Hattori ◽  
Wahab O. Alabi ◽  
B. Rabindran Jermy ◽  
Abdullah M. Aitani ◽  
Sulaiman S. Al-Khattaf
Keyword(s):  

2015 ◽  
Vol 22 (5) ◽  
pp. 1179-1186 ◽  
Author(s):  
Zhihui Zhang ◽  
Wenlan Shan ◽  
Hui Li ◽  
Wanchun Zhu ◽  
Nan Zhang ◽  
...  

Author(s):  
Kent McDonald ◽  
David Mastronarde ◽  
Rubai Ding ◽  
Eileen O'Toole ◽  
J. Richard McIntosh

Mammalian spindles are generally large and may contain over a thousand microtubules (MTs). For this reason they are difficult to reconstruct in three dimensions and many researchers have chosen to study the smaller and simpler spindles of lower eukaryotes. Nevertheless, the mammalian spindle is used for many experimental studies and it would be useful to know its detailed structure.We have been using serial cross sections and computer reconstruction methods to analyze MT distributions in mitotic spindles of PtK cells, a mammalian tissue culture line. Images from EM negatives are digtized on a light box by a Dage MTI video camera containing a black and white Saticon tube. The signal is digitized by a Parallax 1280 graphics device in a MicroVax III computer. Microtubules are digitized at a magnification such that each is 10-12 pixels in diameter.


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