Thermal inactivation and conformational lock studies on glucose oxidase

In this study, the dissociative thermal inactivation and conformational lock theories are applied for the homodimeric enzyme glucose oxidase (GOD) in order to analyze its structure. For this purpose, the rate of activity reduction of glucose oxidase is studied at various temperatures using b-D-glucose as the substrate by incubation of enzyme at various temperatures in the wide range between 40 and 70 �C using UV–Vis spectrophotometry. It was observed that in the two ranges of temperatures, the enzyme has two different forms. In relatively low temperatures, the enzyme is in its dimeric state and has normal activity. In high temperatures, the activity almost disappears and it aggregates. The above achievements are confirmed by dynamic light scattering. The experimental parameter ‘‘n’’ as the obvious number of conformational locks at the dimer interface of glucose oxidase is obtained by kinetic data, and the value is near to two. To confirm the above results, the X-ray crystallography structure of the enzyme, GOD (pdb, 1gal), was also studied. The secondary and tertiary structures of the enzyme to track the thermal inactivation were studied by circular dichroism and fluorescence spectroscopy, respectively. We proposed a mechanism model for thermal inactivation of GOD based on the absence of the monomeric form of the enzyme by circular dichroism and fluorescence spectroscopy

A kinetic model and simulation of starch saccharification and simultaneous ethanol fermentation by amyloglucosidase and Zymomonas mobilis

A mathematical model is described for the simultaneous saccharification and ethanol fermentation (SSF) of sago starch using amyloglucosidase (AMG) and Zymomonas mobilis. By introducing the degree of polymerization (DP) of oligosaccharides produced from sago starch treated with α -amylase, a series of Michaelis-Menten equations were obtained. After determining kinetic parameters from the results of simple experiments carried out at various substrate and enzyme concentrations and from the subsite mapping theory, this model was adapted to simulate the SSF process. The results of simulation for SSF are in good agreement with experimental results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47811/1/449_2004_Article_BF00369488.pd

Possibility of upgrading fighter aircraft MiG-29 in the field of helmet-mounted display systems

The article presents selected results of the analytical work carried out in the Air Force Institute of Technology in the field of information visualization capabilities of helmet-mounted guidance and navigation in fighter aircraft MiG- 29. There is presented the SzCz-3UM headset system of target’s indication, currently used on-board of MiG-29, which is directly cooperating with the pilot during the combat flight. There was presented that the information from the onboard systems of this aircraft containing analogue devices must be computer-processed into digital form in order to present flight data in the helmet-mounted display system. However, MiG-29 aircraft, used in the Polish Air Force, are equipped with modern digital avionics (integrated avionics system) based on the MIL-1553B digital data buses, which gives the possibility of the new helmet-mounted imaging of flight parameters via the computer data processing from aircraft’s devices and on-board installations. To develop guidelines for the construction of the helmet-mounted system for the MiG-29, the SWPL-1 Cyklop flight data-displaying system was adopted (system developed in the Air Force Institute of Technology as avionics system modernization for Mi-17 military helicopters). There are discussed the main problems of scientific and specialist research positions used in the Air Force Institute of Technology to assess the accuracy of the selected equipment components of avionics systems and determine credibility of information provided to the pilot during the flight