Design and synthesis of analogues of ionomycin

1994 ◽  
Vol 72 (6) ◽  
pp. 1500-1511 ◽  
Author(s):  
Thomas Q. Hu ◽  
Larry Weller
Keyword(s):  
Crystal Structure ◽  
Structural Features ◽  
Lipid Solubility ◽  
Carboxyl Group ◽  
Synthetic Route ◽  
Design And Synthesis ◽  
Coordination Sites ◽  
Physical Data ◽  
Oxygen Coordination

Based on the analysis of the crystal structure of the Ca2+ salt of ionomycin and the chemical and physical data on ionomycin, a number of ionomycin analogues have been synthesized to study the structural features affecting the Ca2+ binding and transport. Compounds 2, 3, and 4 were synthesized to study the effect of additional intramolecular oxygen coordination sites on Ca2+ transport. Compounds 5a–5d were prepared to study the effect of lipid solubility on Ca2+ binding and transport. Compounds 6a–6c were prepared to study the effect of the distance between the β-diketone and the carboxyl group on Ca2+ transport. A general synthetic route to these compounds has been developed. The key reactions in this route are the consecutive regioselective alkylations of the dianion of 2,4-pentanedione with the appropriate bromides.[Formula: see text]

scholarly journals The crystal structure of the first ether solvate of hexaphenyldistannane [(Ph3Sn)2 • 2 THF]

2020 ◽  
Vol 43 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Jonathan O. Bauer
Keyword(s):  
Crystal Structure ◽  
Inclusion Compounds ◽  
Molecular Crystal ◽  
Structural Features ◽  
Structural Investigations ◽  
Crystal Solvates

AbstractStructural investigations of molecular crystal solvates can provide important information for the targeted crystallization of particular inclusion compounds. Here, the crystal structure of the first ether solvate of hexaphenyldistannane [(Ph3Sn)2 • 2 THF] is reported. Structural features in terms of host-guest interactions and in the context of the previously reported polymorphs and solvates of (Ph3Sn)2 are discussed.

A 35-year-old mystery solved: a facile synthetic route and structural confirmation of tetrachlorobis(diethyl ether)tungsten(IV)

2021 ◽  
Vol 77 (4) ◽  
Author(s):  
Thomas E. Shaw ◽  
Alfred P. Sattelberger ◽  
Titel Jurca
Keyword(s):  
Crystal Structure ◽  
Diethyl Ether ◽  
Thermal Instability ◽  
Room Temperature ◽  
Surface Characteristics ◽  
Hirshfeld Surface ◽  
Asymmetric Unit ◽  
Synthetic Route ◽  
X Ray ◽  
Elemental Analyses

The true identity of the diethyl ether adduct of tungsten(IV) chloride, WCl4(Et2O) x , has been in doubt since 1985. Initially postulated as the bis-adduct, WCl4(Et2O)2, questions arose when elemental analyses were more in line with a mono-ether adduct, viz. WCl4(Et2O). It was proposed that this was due to the thermal instability of the bis-adduct. Here, we report the room-temperature X-ray crystal structure and Hirshfeld surface characteristics of trans-tetrachloridobis(diethyl ether)tungsten(IV), trans-WCl4(Et2O)2 or trans-[WCl4(C4H10O)2]. The compound crystallizes, with half of the molecule in the asymmetric unit, in the centrosymmetric space group P21/n. The W—O distance is 2.070 (2) Å, while the W—Cl distances are 2.3586 (10) and 2.3554 (10) Å.

Structural insights into dihydroxylation of terephthalate, a product of polyethylene terephthalate degradation

2022 ◽  
Author(s):  
Jai Krishna Mahto ◽  
Neetu Neetu ◽  
Monica Sharma ◽  
Monika Dubey ◽  
Bhanu Prakash Vellanki ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Substrate Specificity ◽  
Polyethylene Terephthalate ◽  
Active Site ◽  
Catalytic Domain ◽  
Structural Features ◽  
Comamonas Testosteroni ◽  
Plastic Pollution ◽  
Microbial Utilization ◽  
Steady State Kinetics

Biodegradation of terephthalate (TPA) is a highly desired catabolic process for the bacterial utilization of this Polyethylene terephthalate (PET) depolymerization product, but to date, the structure of terephthalate dioxygenase (TPDO), a Rieske oxygenase (RO) that catalyzes the dihydroxylation of TPA to a cis -diol is unavailable. In this study, we characterized the steady-state kinetics and first crystal structure of TPDO from Comamonas testosteroni KF1 (TPDO KF1 ). The TPDO KF1 exhibited the substrate specificity for TPA ( k cat / K m = 57 ± 9 mM −1 s −1 ). The TPDO KF1 structure harbors characteristics RO features as well as a unique catalytic domain that rationalizes the enzyme’s function. The docking and mutagenesis studies reveal that its substrate specificity to TPA is mediated by Arg309 and Arg390 residues, two residues positioned on opposite faces of the active site. Additionally, residue Gln300 is also proven to be crucial for the activity, its substitution to alanine decreases the activity ( k cat ) by 80%. Together, this study delineates the structural features that dictate the substrate recognition and specificity of TPDO. Importance The global plastic pollution has become the most pressing environmental issue. Recent studies on enzymes depolymerizing polyethylene terephthalate plastic into terephthalate (TPA) show some potential in tackling this. Microbial utilization of this released product, TPA is an emerging and promising strategy for waste-to-value creation. Research from the last decade has discovered terephthalate dioxygenase (TPDO), as being responsible for initiating the enzymatic degradation of TPA in a few Gram-negative and Gram-positive bacteria. Here, we have determined the crystal structure of TPDO from Comamonas testosteroni KF1 and revealed that it possesses a unique catalytic domain featuring two basic residues in the active site to recognize TPA. Biochemical and mutagenesis studies demonstrated the crucial residues responsible for the substrate specificity of this enzyme.

Peroxisomal multifunctional enzyme type 2 from the fruitfly: dehydrogenase and hydratase act as separate entities, as revealed by structure and kinetics

2011 ◽  
Vol 435 (3) ◽  
pp. 771-781 ◽  
Author(s):  
Tatu J. K. Haataja ◽  
M. Kristian Koski ◽  
J. Kalervo Hiltunen ◽  
Tuomo Glumoff
Keyword(s):  
Crystal Structure ◽  
Saccharomyces Cerevisiae ◽  
Drosophila Melanogaster ◽  
Structural Features ◽  
Full Length ◽  
Multifunctional Enzyme ◽  
Domain Composition ◽  
Substrate Channelling

All of the peroxisomal β-oxidation pathways characterized thus far house at least one MFE (multifunctional enzyme) catalysing two out of four reactions of the spiral. MFE type 2 proteins from various species display great variation in domain composition and predicted substrate preference. The gene CG3415 encodes for Drosophila melanogaster MFE-2 (DmMFE-2), complements the Saccharomyces cerevisiae MFE-2 deletion strain, and the recombinant protein displays both MFE-2 enzymatic activities in vitro. The resolved crystal structure is the first one for a full-length MFE-2 revealing the assembly of domains, and the data can also be transferred to structure–function studies for other MFE-2 proteins. The structure explains the necessity of dimerization. The lack of substrate channelling is proposed based on both the structural features, as well as by the fact that hydration and dehydrogenation activities of MFE-2, if produced as separate enzymes, are equally efficient in catalysis as the full-length MFE-2.

Crystal Structure of Human Dual-Specificity Tyrosine-Regulated Kinase 3 Reveals New Structural Features and Insights into its Auto-phosphorylation

2018 ◽  
Vol 430 (10) ◽  
pp. 1521-1530 ◽  
Author(s):  
Kuglae Kim ◽  
Jeong Seok Cha ◽  
Yong-Soon Cho ◽  
Hoyoung Kim ◽  
Nienping Chang ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structural Features ◽  
Dual Specificity

scholarly journals A Physical Organic Approach to Tuning Reagents for Selective and Stable Methionine Bioconjugation

2019 ◽  
Author(s):  
Alec Christian ◽  
Shang Jia ◽  
Patricia Zhang ◽  
Arismel Tena Meza ◽  
Matthew S. Sigman ◽  
...  
Keyword(s):  
Structural Features ◽  
Data Driven ◽  
Live Cells ◽  
Design And Synthesis ◽  
Use Of Data ◽  
Physical Organic ◽  
Driving Stability ◽  
Peptide Stapling ◽  
Insight Into ◽  
Unique Chemical

We report a data-driven, physical organic approach to the development of new methionine-selective bioconjugation reagents with tunable adduct stabilities. Statistical modeling of structural features described by intrinsic physical organic parameters was applied to the development of a predictive model and to gain insight into features driving stability of adducts formed from the chemoselective coupling of oxaziridine and methionine thioether partners through Redox Activated Chemical Tagging (ReACT). From these analyses, a correlation between sulfimide stabilities and sulfimide  (C=O) stretching frequencies was revealed. We ex-ploited the rational gains in adduct stability exposed by this analysis to achieve the design and synthesis of a bis-oxaziridine reagent for peptide stapling. Indeed, we observed that a macrocyclic peptide formed by ReACT stapling at methionine exhibited improved uptake into live cells compared to an unstapled congener, highlighting the potential utility of this unique chemical tool for thioether modification. This work provides a template for the broader use of data-driven approaches to bioconjugation chemistry and other chemical biology applications.

The alternative oxidases: simple oxidoreductase proteins with complex functions

2013 ◽  
Vol 41 (5) ◽  
pp. 1305-1311 ◽  
Author(s):  
Luke Young ◽  
Tomoo Shiba ◽  
Shigeharu Harada ◽  
Kiyoshi Kita ◽  
Mary S. Albury ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Transport ◽  
Alternative Oxidase ◽  
Structural Features ◽  
Transport Proteins ◽  
Integral Membrane Proteins ◽  
Complex Functions ◽  
Membrane Bound ◽  
Iron Carboxylate ◽  
Electron Transport Proteins

The alternative oxidases are membrane-bound monotopic terminal electron transport proteins found in all plants and in some agrochemically important fungi and parasites including Trypansoma brucei, which is the causative agent of trypanosomiasis. They are integral membrane proteins and reduce oxygen to water in a four electron process. The recent elucidation of the crystal structure of the trypanosomal alternative oxidase at 2.85 Å (1 Å=0.1 nm) has revealed salient structural features necessary for its function. In the present review we compare the primary and secondary ligation spheres of the alternative oxidases with other di-iron carboxylate proteins and propose a mechanism for the reduction of oxygen to water.

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