Heat-resistant structural features of bovine β-lactoglobulin A revealed by NMR H/D exchange observations

2002 ◽  
Vol 12 (4) ◽  
pp. 331-344 ◽  
Author(s):  
Patrick J.B Edwards ◽  
Geoffrey B Jameson ◽  
Kate P Palmano ◽  
Lawrence K Creamer
1994 ◽  
Vol 48 (10) ◽  
pp. 1255-1264 ◽  
Author(s):  
Vincent E. Turula ◽  
James A. de Haseth

The efficacy of the particle beam LC/FT-IR interface, in its development as a tool for the determination of dynamic protein structure from experiments such as HPLC separations and folding/refolding intermediate analysis, is presented here. The particle beam apparatus can be used to desolvate proteins rapidly in preparation of IR measurements. Several experiments have been designed to determine whether the operation of the particle beam apparatus causes alteration to the complex structural features of globular proteins, and whether it produces a solid-state spectrum representative of protein solution structure. It is shown here that the structural integrity of β-lactoglobulin is maintained when nebulized, desolvated from solution, and deposited onto the IR-substrate. Since enzyme activity is dependent upon the maintenance of higher-order structure, a complementary series of spectrophotometric-activity experiments with lysozyme collected from the particle beam were performed to determine the state of the tertiary and quaternary structures. The lysozyme particle beam deposit not only produced a secondary structure estimate similar to that of solution; it also retained its biological activity. It is demonstrated that the particle beam can induce structural changes in proteins with a carrier-liquid concentration gradient; this characteristic is useful for band assignment.


2011 ◽  
Vol 1218 (22) ◽  
pp. 3423-3431 ◽  
Author(s):  
Pasquale Ferranti ◽  
Gianfranco Mamone ◽  
Gianluca Picariello ◽  
Francesco Addeo

2019 ◽  
Vol 60 (11-12) ◽  
pp. 739-744 ◽  
Author(s):  
D. V. Masaylo ◽  
A. A. Popovich ◽  
V. Sh. Sufiyarov ◽  
A. V. Orlov ◽  
A. I. Shamshurin

2016 ◽  
pp. 76-82 ◽  
Author(s):  
E. A. Lukina ◽  
◽  
S. V. Ovsepyan ◽  
E. A. Davydova ◽  
M. V. Akhmedzyanov ◽  
...  

1998 ◽  
Vol 46 (6) ◽  
pp. 2159-2166 ◽  
Author(s):  
Stefania Iametti ◽  
Leonardo Scaglioni ◽  
Stefania Mazzini ◽  
Giuseppe Vecchio ◽  
Francesco Bonomi

2021 ◽  
Vol 2 ◽  
pp. 5-15
Author(s):  
Yu. A. Bondarenko ◽  
◽  
M. Yu. Kolodyazhnyy ◽  
V. A. V. A. ◽  
◽  
...  

The scientific, technical and technological aspects in the field of creating new high-temperature materials for the hot tract parts of gas turbine engines (GTE) with operating temperatures exceeding those existing in the GTE are considered. Investigated more refractory metal materials to create new high-temperature alloys used in the manufacture of working and nozzle blades and other parts of promising gas turbine engines based on Co – Cr, Pt – Al, Nb – Si, Mo – Si – B systems. In Co – Cr alloys, heat resistance is mainly ensured by hardening the Co matrix, including dispersed precipitates of the carbide phase (TaC) and the boride phase Cr2B. In alloys of the Pt – Al system, due to the doping of Cr, Al, Ti, Re ... and precipitates of the coherently embedded Pt3Al phase. In eutectic alloys of the Nb-Si system, this is due to complex hardening of the Nb solid solution and Nb5Si3 silicide, as well as the natural compositional structure. In Mo – Si – B alloys, high strength is achieved by doping a-Mo solid solution and the formation of intermetallic phases Mo3Si, Mo5SiB2, carbides Mo2C, TiC. Compositions were selected, analysis of their smelting methods was carried out, including directed crystallization, which provides a natural compositional structure, mechanical properties at room and high temperatures, oxidation resistance were evaluated, structural features were investigated, information was provided on technological equipment and the possibility of obtaining parts in various ways. It is shown that, depending on the composition of the selected matrix, the working temperature of heat-resistant alloys can increase to 1300 – 1500 °C, which significantly exceeds the existing nickel heat-resistant alloys. It is concluded that the materials under study are promising for use in aircraft engine building and the aerospace industry.


Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.


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