scholarly journals STRUCTURAL DETERMINATION OF L-ASPARAGINASE II OF STREPTOMYCES ALBIDOFLAVUS AND INTERACTION ANALYSIS WITH L-ASPARAGINE AND CEFOTAXIME

Author(s):  
ACHYUTUNI VENKATA NAGA TEJASWINI ◽  
MALOTHU RAMESH

Objective: L-Asparaginase enzyme possesses a crucial role in the treatment of various hematologic malignancies. The current study focuses on homology modeling and interaction analysis of L-Asparaginase proteins belonging to Streptomyces albidoflavus (S. albidoflavus) with the essential ligand L-Asparagine and subsequent analysis with essential β-lactam antibiotic Cefotaxime. Methods: The process of understanding Asparaginase interactions primarily involved structure determination of WP_096097608, WP_095730301, which is achieved by GalaxyTBM, I-TASSER and SWISS-MODEL. Further, the S. albidoflavus Asparaginase proteins are subjected to GalaxySite and Autodock Vina of PyRx analysis. Results: The GalaxyTBM predicted structures of both the proteins are found promising on various validation studies. The two Asparaginase proteins exhibited high binding affinities of-6.8 and-6.5 kcal/mol with Cefotaxime and-5.1 and-4.9 kcal/mol towards Asparagine. The protein WP_096097608 residues forming hydrogen bonds with L-Asparagine are also analysed to involve in interaction with Cefotaxime on individual docking analysis. Conclusion: The current findings details the two S. albidoflavus Asparaginase proteins affinity towards L-Asparagine, hence can be assessed further for immunogenicity studies. In addition to the above findings, an attempt is made to find the L-Asparaginase binding possibilities with non-metals that identified an essential β-lactam antibiotic Cefotaxime to be an effective inhibitor. This study helps in understanding the interactions of L-Asparaginase with Cefotaxime, as intake of antibiotics between the phases of chemotherapy is observed to treat various infections and also as an antibiotic to microbes that utilize Asparaginase as a vital enzyme.

2004 ◽  
Author(s):  
Ya-Ling Wu ◽  
Geoffrey L. Greene

2020 ◽  
Vol 17 (3) ◽  
pp. 206-210
Author(s):  
Ty Viet Pham ◽  
Thang Quoc Le ◽  
Anh Tuan Le ◽  
Hung Quoc Vo ◽  
Duc Viet Ho

A phytochemical investigation of the leaves of Annona reticulata led to the isolation and structural determination of β-sitosterol (1), ent-pimara-8(14),15-dien-19-oic acid (2), ent-pimara- 8(14),15-dien-19-ol (3), quercetin (4), quercetin 3-O-α-L-arabinopyranoside (5), and a mixture of quercetin 3-O-β-D-galactopyranoside (6a) and quercetin 3-O-β-D-glucopyranoside (6b). Of these, compounds 2 and 3 were isolated from the genus Annona for the first time. Compound 3 showed strong cytotoxicity against SK-LU-1 and SW626 cell lines with IC50 values of 17.64 ± 1.07 and 19.79 ± 1.41 μg mL-1, respectively.


Author(s):  
Yasujiro Murata ◽  
Shih-Ching Chuang ◽  
Fumiyuki Tanabe ◽  
Michihisa Murata ◽  
Koichi Komatsu

We present our study on the recognition of hydrogen isotopes by an open-cage fullerene through determination of binding affinity of isotopes H 2 /HD/D 2 with the open-cage fullerene and comparison of their relative molecular sizes through kinetic-isotope-release experiments. We took advantage of isotope H 2 /D 2 exchange that generated an equilibrium mixture of H 2 /HD/D 2 in a stainless steel autoclave to conduct high-pressure hydrogen insertion into an open-cage fullerene. The equilibrium constants of three isotopes with the open-cage fullerene were determined at various pressures and temperatures. Our results show a higher equilibrium constant for HD into open-cage fullerene than the other two isotopomers, which is consistent with its dipolar nature. D 2 molecule generally binds stronger than H 2 because of its heavier mass; however, the affinity for H 2 becomes larger than D 2 at lower temperature, when size effect becomes dominant. We further investigated the kinetics of H 2 /HD/D 2 release from open-cage fullerene, proving their relative escaping rates. D 2 was found to be the smallest and H 2 the largest molecule. This notion has not only supported the observed inversion of relative binding affinities between H 2 and D 2 , but also demonstrated that comparison of size difference of single molecules through non-convalent kinetic-isotope effect was applicable.


1998 ◽  
Vol 54 (3) ◽  
pp. 345-350 ◽  
Author(s):  
L. E. Hall ◽  
D. R. McKenzie ◽  
R. L. Davis ◽  
M. I. Attalla ◽  
A. M. Vassallo

A mixture of C60D36 with 24.5 \pm 4.5% C60 by weight has been analysed by neutron diffraction techniques. The diffraction data was converted to a reduced density function G(r) by Fourier transformation. The C60 component of the G(r) was subtracted out. This enabled a comparison for five molecular models of C60D36, with symmetries T, Th , S 6 and two D 3 d isomers, with the experimental G(r). This specimen of C60D36 was found to be best described by a T symmetry isomer, in agreement with 13C NMR and IR data for C60H36 [Attalla et al. (1993). J. Phys. Chem. pp. 6329–6331].


2009 ◽  
Vol 42 (24) ◽  
pp. 9523-9527 ◽  
Author(s):  
John R. Ell ◽  
Dennis E. Mulder ◽  
Roland Faller ◽  
Timothy E. Patten ◽  
Tonya L. Kuhl

Author(s):  
Chen Zhu ◽  
Tenfei Duan ◽  
Hao Li ◽  
Xiao Wei ◽  
Xi Kang ◽  
...  

Research on nanocluster transformation has generally focused on stable nanoclusters, while analysis on structure evolutions of metastable nanoclusters just began to receive attention recently. Herein, we reported the structure determination...


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