A New Rearrangement Reaction of β-Hydroxy-α-amino Acid <i>N</i>-Carboxy Anhydrides to 2-Oxazolidone Derivatives

Saito, Tomoo

doi:10.1246/bcsj.37.624

Cited by 13 publications

(4 citation statements)

References 4 publications

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“…The rearrangement of the NCA to the oxazolidinone has been previously documented under anhydrous basic conditions. 51 However, basic conditions do not appear to be required since this rearrangement occurs in DMSO, although slowly.…”

Section: ■ Discussionmentioning

confidence: 99%

Mechanism of N6-Threonylcarbamoyladenonsine (t⁶A) Biosynthesis: Isolation and Characterization of the Intermediate Threonylcarbamoyl-AMP

Lauhon

2012

Biochemistry

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Genetic and biochemical studies have recently implicated four proteins required in bacteria for the biosynthesis of the universal tRNA modified base N6-threonylcarbamoyl adenosine (t(6)A). In this work, t(6)A biosynthesis in Bacillus subtilis has been reconstituted in vitro and found to indeed require the four proteins YwlC (TsaC), YdiB (TsaE), YdiC (TsaB) and YdiE (TsaD). YwlC was found to catalyze the conversion of L-threonine, bicarbonate/CO(2) and ATP to give the intermediate L-threonylcarbamoyl-AMP (TC-AMP) and pyrophosphate as products. TC-AMP was isolated by HPLC and characterized by mass spectrometry and (1)H NMR. NMR analysis showed that TC-AMP decomposes to give AMP and a nearly equimolar mixture of L-threonine and 5-methyl-2-oxazolidinone-4-carboxylate as final products. Under physiological conditions (pH 7.5, 37 °C, 2 mM MgCl(2)), the half-life of TC-AMP was measured to be 3.5 min. Both YwlC (in the presence of pyrophosphatase) and its Escherichia coli homologue YrdC catalyze the formation of TC-AMP while producing only a small molar fraction of AMP. This suggests that CO(2) and not an activated form of bicarbonate is the true substrate for these enzymes. In the presence of pyrophosphate, both enzymes catalyze clean conversion of TC-AMP back to ATP. Purified TC-AMP is efficiently processed to t(6)A by the YdiBCE proteins in the presence of tRNA substrates. This reaction is ATP independent in vitro, despite the known ATPase activity of YdiB. The estimated rate of conversion of TC-AMP by YdiBCE to t(6)A is somewhat lower than the initial rate from L-threonine, bicarbonate and ATP, which together with the stability data, is consistent with previous studies that suggest channeling of this intermediate.

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Section: ■ Discussionmentioning

confidence: 99%

Mechanism of N6-Threonylcarbamoyladenonsine (t⁶A) Biosynthesis: Isolation and Characterization of the Intermediate Threonylcarbamoyl-AMP

Lauhon

2012

Biochemistry

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“…Treatment of the amino acid with phosgene in dioxane was reported to generate the NCA; however, the product was only characterized by elemental analysis and was not polymerized. Similarly, in 1964, Saito reported that free β-OH Thr NCA could be formed but polymerization attempts led to rearrangement to the 2-oxazolidinone derivative rather than the polypeptide . Recent work on free β-OH Thr NCA has also shown that epimerization of the α-carbon leads to diastereomers .…”

Section: Introductionmentioning

confidence: 98%

“…Similarly, in 1964, Saito reported that free β-OH Thr NCA could be formed but polymerization attempts led to rearrangement to the 2-oxazolidinone derivative rather than the polypeptide. 16 Recent work on free β-OH Thr NCA has also shown that epimerization of the α-carbon leads to diastereomers. 17 Therefore, NCA studies have used various β-OH-protected Thrs including trimethylsilyl (TMS), 18,19 tertbutyl, 20 benzyl (Bn), 21 and diphenylphosphate 22 as protecting or functional groups.…”

Section: ■ Introductionmentioning

confidence: 99%

Biomimetic Glycosylated Polythreonines by N-Carboxyanhydride Polymerization

Deleray

Kramer

2022

Biomacromolecules

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Glycosylated threonine (Thr) is a structural motif found in seemingly disparate natural proteins from deep-sea collagen to mucins. Synthetic mimics of these important proteins are of great interest in biomedicine. Such materials also provide ready access to probe the contributions of individual amino acids to protein structure in a controlled and tunable manner. N-Carboxyanhydride (NCA) polymerization is one major route to such biomimetic polypeptides. However, challenges in the preparation and polymerization of Thr NCAs have impeded obtaining such structures. Here, we present optimized routes to several glycosylated and acetylated Thr NCAs of high analytical purity. Transition metal catalysis produced tunable homo-, statistical, and block-polypeptides with predictable chain lengths and low dispersities. We conducted structural work to examine their aqueous conformations and found that a high content of free OH Thr induces the formation of water-insoluble β-sheets. However, glycosylation appears to induce a polyproline II-type helical conformation, which sheds light on the role of glyco-Thr in rigid proteins such as mucins and collagen.

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“…In view of the short lifetimes predicted for the triplet state4 it is possible that the weak signal is due to small amounts of naphthalene impurity. (10) Weak Am = 1 transitions were observed in the spectrum for the photoexcited triplet of the 1:1 azulene-boron trifluoride complex. However, it is not clear whether these are due to a triplet of the complex or to the presence of azulenium ions formed by reaction with trace amounts of HsO-BFs.…”

Section: Sirmentioning

confidence: 95%

The Photoexcited Triplet State of the Azulenium Cation¹

Blears¹,

Danyluk²

1966

J. Am. Chem. Soc.

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A New Rearrangement Reaction of β-Hydroxy-α-amino Acid N-Carboxy Anhydrides to 2-Oxazolidone Derivatives

Cited by 13 publications

References 4 publications

Mechanism of N6-Threonylcarbamoyladenonsine (t⁶A) Biosynthesis: Isolation and Characterization of the Intermediate Threonylcarbamoyl-AMP

Mechanism of N6-Threonylcarbamoyladenonsine (t⁶A) Biosynthesis: Isolation and Characterization of the Intermediate Threonylcarbamoyl-AMP

Biomimetic Glycosylated Polythreonines by N-Carboxyanhydride Polymerization

The Photoexcited Triplet State of the Azulenium Cation¹

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A New Rearrangement Reaction of β-Hydroxy-α-amino Acid N-Carboxy Anhydrides to 2-Oxazolidone Derivatives

Cited by 13 publications

References 4 publications

Mechanism of N6-Threonylcarbamoyladenonsine (t6A) Biosynthesis: Isolation and Characterization of the Intermediate Threonylcarbamoyl-AMP

Mechanism of N6-Threonylcarbamoyladenonsine (t6A) Biosynthesis: Isolation and Characterization of the Intermediate Threonylcarbamoyl-AMP

Biomimetic Glycosylated Polythreonines by N-Carboxyanhydride Polymerization

The Photoexcited Triplet State of the Azulenium Cation1

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Mechanism of N6-Threonylcarbamoyladenonsine (t⁶A) Biosynthesis: Isolation and Characterization of the Intermediate Threonylcarbamoyl-AMP

Mechanism of N6-Threonylcarbamoyladenonsine (t⁶A) Biosynthesis: Isolation and Characterization of the Intermediate Threonylcarbamoyl-AMP

The Photoexcited Triplet State of the Azulenium Cation¹