1.Comparative Modeling and Molecular Dynamics Simulation of Substrate Binding in Human Fatty Acid Synthase: Enoyl Reductase and beta-Ketoacyl Reductase Catalytic Domains.
Arun JOHN ; Vetrivel UMASHANKAR ; Subramanian KRISHNAKUMAR ; Perinkulam Ravi DEEPA
Genomics & Informatics 2015;13(1):15-24
Fatty acid synthase (FASN, EC 2.3.1.85), is a multi-enzyme dimer complex that plays a critical role in lipogenesis. This lipogenic enzyme has gained importance beyond its physiological role due to its implications in several clinical conditions-cancers, obesity, and diabetes. This has made FASN an attractive pharmacological target. Here, we have attempted to predict the theoretical models for the human enoyl reductase (ER) and beta-ketoacyl reductase (KR) domains based on the porcine FASN crystal structure, which was the structurally closest template available at the time of this study. Comparative modeling methods were used for studying the structure-function relationships. Different validation studies revealed the predicted structures to be highly plausible. The respective substrates of ER and KR domains-namely, trans-butenoyl and beta-ketobutyryl-were computationally docked into active sites using Glide in order to understand the probable binding mode. The molecular dynamics simulations of the apo and holo states of ER and KR showed stable backbone root mean square deviation trajectories with minimal deviation. Ramachandran plot analysis showed 96.0% of residues in the most favorable region for ER and 90.3% for the KR domain, respectively. Thus, the predicted models yielded significant insights into the substrate binding modes of the ER and KR catalytic domains and will aid in identifying novel chemical inhibitors of human FASN that target these domains.
Catalytic Domain*
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Humans
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Lipogenesis
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Models, Theoretical
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Molecular Dynamics Simulation*
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Obesity
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Oxidoreductases*
2.Composite Grip Strength as a Marker of Outcome in Patients Surgically Treated for Degenerative Cervical Myelopathy
Arun John PAUL ; Rohit AMRITANAND ; Prabakaran MARGABANDHU ; Reka KARUPPUSAMI ; Kenny Samuel DAVID ; Venkatesh KRISHNAN
Asian Spine Journal 2021;15(5):664-672
Methods:
This retrospective study was performed on degenerative cervical myelopathy patients with a complete composite grip strength assessment between January 2013 to January 2019. The Biometrics E-link hand kit was used for the assessment. The following parameters were measured: maximum grip strength, sustained grip strength, three-jaw pinch, maximum key pinch, and sustained key pinch. The pre- and postoperative functional status was assessed using the Nurick grade and the modified Japanese Orthopaedic Association (mJOA) score.
Results:
A total of 40 patients were included in the study. The mean patient age was 51.9 years. The mean preoperative Nurick grade was 3.5 and the mJOA score was 10.9. The anterior approach was used in 25 patients, and the posterior approach was used in 15 patients. Four patients developed complications. Degenerative cervical myelopathy resulted in decreased handgrip and pinch strength as compared to normative Indian data. There was a significant improvement in the postoperative composite grip strength for all five parameters. There was no differential improvement between the anterior and posterior surgical groups. The improvement in the composite grip strength correlated with the improvement in functional scores.
Conclusions
Composite grip strength analysis is an objective method for assessing the impact of degenerative cervical myelopathy on grip strength and monitoring the postoperative improvement. Decompressive surgery resulted in global improvement in all the parameters of composite grip strength.