Chimeric Investigations into the Diamide Binding Site on the Lepidopteran Ryanodine Receptor

Alterations to amino acid residues G4946 and I4790, associated with resistance to diamide insecticides, suggests a location of diamide interaction within the pVSD voltage sensor-like domain of the insect ryanodine receptor (RyR). To further delineate the interaction site(s), targeted alterations were made within the same pVSD region on the diamondback moth (Plutella xylostella) RyR channel. The editing of five amino acid positions to match those found in the diamide insensitive skeletal RyR1 of humans (hRyR1) in order to generate a human–Plutella chimeric construct showed that these alterations strongly reduce diamide efficacy when introduced in combination but cause only minor reductions when introduced individually. It is concluded that the sites of diamide interaction on insect RyRs lie proximal to the voltage sensor-like domain of the RyR and that the main site of interaction is at residues K4700, Y4701, I4790 and S4919 in the S1 to S4 transmembrane domains.

Download Full-text

Schistosomal Sulfotransferase Interaction with Oxamniquine Involves Hybrid Mechanism of Induced-fit and Conformational Selection

Current Computer - Aided Drug Design ◽

10.2174/1573409915666190708103132 ◽

2020 ◽

Vol 16 (4) ◽

pp. 451-459 ◽

Cited By ~ 1

Author(s):

Fortunatus C. Ezebuo ◽

Ikemefuna C. Uzochukwu

Keyword(s):

Molecular Dynamics ◽

Amino Acid ◽

Binding Energy ◽

Binding Site ◽

Conformational Dynamics ◽

Side Chain ◽

Amino Acid Residues ◽

Conformational Selection ◽

Hybrid Mechanism ◽

Dynamics Simulations

Background: Sulfotransferase family comprises key enzymes involved in drug metabolism. Oxamniquine is a pro-drug converted into its active form by schistosomal sulfotransferase. The conformational dynamics of side-chain amino acid residues at the binding site of schistosomal sulfotransferase towards activation of oxamniquine has not received attention. Objective: The study investigated the conformational dynamics of binding site residues in free and oxamniquine bound schistosomal sulfotransferase systems and their contribution to the mechanism of oxamniquine activation by schistosomal sulfotransferase using molecular dynamics simulations and binding energy calculations. Methods: Schistosomal sulfotransferase was obtained from Protein Data Bank and both the free and oxamniquine bound forms were subjected to molecular dynamics simulations using GROMACS-4.5.5 after modeling it’s missing amino acid residues with SWISS-MODEL. Amino acid residues at its binding site for oxamniquine was determined and used for Principal Component Analysis and calculations of side-chain dihedrals. In addition, binding energy of the oxamniquine bound system was calculated using g_MMPBSA. Results: The results showed that binding site amino acid residues in free and oxamniquine bound sulfotransferase sampled different conformational space involving several rotameric states. Importantly, Phe45, Ile145 and Leu241 generated newly induced conformations, whereas Phe41 exhibited shift in equilibrium of its conformational distribution. In addition, the result showed binding energy of -130.091 ± 8.800 KJ/mol and Phe45 contributed -9.8576 KJ/mol. Conclusion: The results showed that schistosomal sulfotransferase binds oxamniquine by relying on hybrid mechanism of induced fit and conformational selection models. The findings offer new insight into sulfotransferase engineering and design of new drugs that target sulfotransferase.

Download Full-text

Mitigating the Adverse Effects of Polychlorinated Biphenyl Derivatives on Estrogenic Activity via Molecular Modification Techniques

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094999 ◽

2021 ◽

Vol 18 (9) ◽

pp. 4999

Author(s):

Wei He ◽

Wenhui Zhang ◽

Zhenhua Chu ◽

Yu Li

Keyword(s):

Amino Acid ◽

Binding Site ◽

Hydrophobic Interaction ◽

Oestrogen Receptor ◽

Polychlorinated Biphenyl ◽

Hydrophobic Interactions ◽

Estrogenic Activity ◽

Average Distance ◽

Amino Acid Residues ◽

Hydrophobic Amino Acid

The aim of this paper is to explore the mechanism of the change in oestrogenic activity of PCBs molecules before and after modification by designing new PCBs derivatives in combination with molecular docking techniques through the constructed model of oestrogenic activity of PCBs molecules. We found that the weakened hydrophobic interaction between the hydrophobic amino acid residues and hydrophobic substituents at the binding site of PCB derivatives and human oestrogen receptor alpha (hERα) was the main reason for the weakened binding force and reduced anti-oestrogenic activity. It was consistent with the information that the hydrophobic field displayed by the 3D contour maps in the constructed oestrogen activity CoMSIA model was one of the main influencing force fields. The hydrophobic interaction between PCB derivatives and oestrogen-active receptors was negatively correlated with the average distance between hydrophobic substituents and hydrophobic amino acid residues at the hERα-binding site, and positively correlated with the number of hydrophobic amino acid residues. In other words, the smaller the average distance between the hydrophobic amino acid residues at the binding sites between the two and the more the number of them, and the stronger the oestrogen activity expression degree of PCBS derivative molecules. Therefore, hydrophobic interactions between PCB derivatives and the oestrogen receptor can be reduced by altering the microenvironmental conditions in humans. This reduces the ability of PCB derivatives to bind to the oestrogen receptor and can effectively modulate the risk of residual PCB derivatives to produce oestrogenic activity in humans.

Download Full-text

Binding site amino acid residues of jack fruit (artocarpus integrifolia) seed lectin: chemical modification and protein difference spectral studies

Journal of Biosciences ◽

10.1007/bf02716761 ◽

1985 ◽

Vol 7 (1) ◽

pp. 7-14 ◽

Cited By ~ 6

Author(s):

P. S. Appukuttan ◽

Debkumar Basu

Keyword(s):

Amino Acid ◽

Chemical Modification ◽

Binding Site ◽

Spectral Studies ◽

Amino Acid Residues ◽

Artocarpus Integrifolia

Download Full-text

Amino Acid Residues Gln4020and Lys4021of the Ryanodine Receptor Type 1 Are Required for Activation by 4-Chloro-m-cresol

Journal of Biological Chemistry ◽

10.1074/jbc.m600670200 ◽

2006 ◽

Vol 281 (30) ◽

pp. 21022-21031 ◽

Cited By ~ 18

Author(s):

James D. Fessenden ◽

Wei Feng ◽

Isaac N. Pessah ◽

Paul D. Allen

Keyword(s):

Amino Acid ◽

Ryanodine Receptor ◽

Receptor Type ◽

Amino Acid Residues

Download Full-text

The interaction of D-Amino acid residues with the aromatic binding site of α-chymotrypsin

FEBS Letters ◽

10.1016/0014-5793(74)80098-0 ◽

1974 ◽

Vol 38 (2) ◽

pp. 139-142 ◽

Cited By ~ 8

Author(s):

Hans Rudolf Bosshard

Keyword(s):

Amino Acid ◽

Binding Site ◽

Amino Acid Residues

Download Full-text

Identification of amino acid residues responsible for the α5 subunit binding selectivity of L-655,708, a benzodiazepine binding site ligand at the GABAA receptor

Journal of Neurochemistry ◽

10.1046/j.1471-4159.2001.00289.x ◽

2001 ◽

Vol 77 (2) ◽

pp. 445-451 ◽

Cited By ~ 44

Author(s):

M. Anna Casula ◽

Frances A. Bromidge ◽

Gopalan V. Pillai ◽

Peter B. Wingrove ◽

Karine Martin ◽

...

Keyword(s):

Amino Acid ◽

Binding Site ◽

Gabaa Receptor ◽

Amino Acid Residues ◽

Binding Selectivity ◽

Benzodiazepine Binding

Download Full-text

The essential mitotic target of calmodulin is the 110-kilodalton component of the spindle pole body in Saccharomyces cerevisiae

Molecular and Cellular Biology ◽

10.1128/mcb.13.12.7913-7924.1993 ◽

1993 ◽

Vol 13 (12) ◽

pp. 7913-7924

Author(s):

J R Geiser ◽

H A Sundberg ◽

B H Chang ◽

E G Muller ◽

T N Davis

Keyword(s):

Amino Acid ◽

Sequence Analysis ◽

Binding Site ◽

Hybrid System ◽

Spindle Pole Body ◽

Spindle Pole ◽

Amino Acid Residues ◽

Calmodulin Binding ◽

Pole Body ◽

Two Hybrid

Two independent methods identified the spindle pole body component Nuf1p/Spc110p as the essential mitotic target of calmodulin. Extragenic suppressors of cmd1-1 were isolated and found to define three loci, XCM1, XCM2, and XCM3 (extragenic suppressor of cmd1-1). The gene encoding a dominant suppressor allele of XCM1 was cloned. On the basis of DNA sequence analysis, genetic cosegregation, and mutational analysis, XCM1 was identified as NUF1/SPC110. Independently, a C-terminal portion of Nuf1p/Spc110p, amino acid residues 828 to 944, was isolated as a calmodulin-binding protein by the two-hybrid system. As assayed by the two-hybrid system, Nuf1p/Spc110p interacts with wild-type calmodulin and triple-mutant calmodulins defective in binding Ca2+ but not with two mutant calmodulins that confer a temperature-sensitive phenotype. Deletion analysis by the two-hybrid system mapped the calmodulin-binding site of Nuf1p/Spc110p to amino acid residues 900 to 927. Direct binding between calmodulin and Nuf1p/Spc110p was demonstrated by a modified gel overlay assay. Furthermore, indirect immunofluorescence with fixation procedures known to aid visualization of spindle pole body components localized calmodulin to the spindle pole body. Sequence analysis of five suppressor alleles of NUF1/SPC110 indicated that suppression of cmd1-1 occurs by C-terminal truncation of Nuf1p/Spc110p at amino acid residues 856, 863, or 881, thereby removing the calmodulin-binding site.

Download Full-text

Comparison of the Amino Acid Residues in the Sixth Transmembrane Domains Accessible in the Binding-Site Crevices of μ, δ, and κ Opioid Receptors†

Biochemistry ◽

10.1021/bi002490d ◽

2001 ◽

Vol 40 (27) ◽

pp. 8018-8029 ◽

Cited By ~ 17

Author(s):

Wei Xu ◽

Jin Li ◽

Chongguang Chen ◽

Peng Huang ◽

Harel Weinstein ◽

...

Keyword(s):

Amino Acid ◽

Binding Site ◽

Opioid Receptors ◽

Transmembrane Domains ◽

Amino Acid Residues

Download Full-text

A central core disease mutation in the Ca2+-binding site of skeletal muscle ryanodine receptor impairs single-channel regulation

AJP Cell Physiology ◽

10.1152/ajpcell.00052.2019 ◽

2019 ◽

Vol 317 (2) ◽

pp. C358-C365 ◽

Cited By ~ 3

Author(s):

Venkat R. Chirasani ◽

Le Xu ◽

Hannah G. Addis ◽

Daniel A. Pasek ◽

Nikolay V. Dokholyan ◽

...

Keyword(s):

Skeletal Muscle ◽

Amino Acid ◽

Missense Mutation ◽

Ryanodine Receptor ◽

Single Channel ◽

Central Core ◽

Central Core Disease ◽

Hek293 Cells ◽

Amino Acid Residues ◽

Single Channel Recordings

Cryoelectron microscopy and mutational analyses have shown that type 1 ryanodine receptor (RyR1) amino acid residues RyR1-E3893, -E3967, and -T5001 are critical for Ca2+-mediated activation of skeletal muscle Ca2+ release channel. De novo missense mutation RyR1-Q3970K in the secondary binding sphere of Ca2+ was reported in association with central core disease (CCD) in a 2-yr-old boy. Here, we characterized recombinant RyR1-Q3970K mutant by cellular Ca2+ release measurements, single-channel recordings, and computational methods. Caffeine-induced Ca2+ release studies indicated that RyR1-Q3970K formed caffeine-sensitive, Ca2+-conducting channel in HEK293 cells. However, in single-channel recordings, RyR1-Q3970K displayed low Ca2+-dependent channel activity and greatly reduced activation by caffeine or ATP. A RyR1-Q3970E mutant corresponds to missense mutation RyR2-Q3925E associated with arrhythmogenic syndrome in cardiac muscle. RyR1-Q3970E also formed caffeine-induced Ca2+ release in HEK293 cells and exhibited low activity in the presence of the activating ligand Ca2+ but, in contrast to RyR1-Q3970K, was activated by ATP and caffeine in single-channel recordings. Computational analyses suggested distinct structural rearrangements in the secondary binding sphere of Ca2+ of the two mutants, whereas the interaction of Ca2+ with directly interacting RyR1 amino acid residues Glu3893, Glu3967, and Thr5001 was only minimally affected. We conclude that RyR1-Q3970 has a critical role in Ca2+-dependent activation of RyR1 and that a missense RyR1-Q3970K mutant may give rise to myopathy in skeletal muscle.

Download Full-text