Effects of metal ions and pH on the formation and decomposition rates of di- and tri-peptides in aqueous solution

Sakata, K.; Yabuta, Hikaru; Kondo, Tadashi

doi:10.2343/geochemj.2.0300

Cited by 10 publications

(5 citation statements)

References 60 publications

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“…Thus, the experimental value of 1.29 (Equation ), might indicate that the amino acid polymerization was only partial. Actually, transition metal ions (such as Cu 2+ and Zn 2+ ) are known to catalyze the formation of small peptides from free amino acids or their ester derivatives …”

Section: Resultsmentioning

confidence: 99%

Kinetics of the chromium(III)/l‐glutamic acid complexation reaction: Formation, decay, and UV‐vis spectrum of a long‐lived intermediate

Perez‐Benito

Nicolas‐Rivases

2018

Int J of Chemical Kinetics

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The kinetics of the aqueous reaction of Cr(III) with either L-glutamic acid or sodium hydrogen L-glutamate at pH 2.46-5.87 have been followed by means of absorbance readings. The rate of formation of the reaction products showed accelerationdeceleration periods, caused by the accumulation and posterior decay of an intermediate in nonnegligible concentration. A double-exponential integrated rate law allowed obtaining two rate constants for each absorbance-time experimental series, associated with the appearance (k 1 ) and decay (k 2 ) of the long-lived intermediate. An increase of the initial concentrations of either hydrogen L-glutamate (apparent kinetic orders < 1) or hydroxide (kinetic orders = 1) ions resulted in an increase of both k 1 and k 2 , but addition of an inert electrolyte (KNO 3 ) resulted in opposite effects on k 1 (decrease) and k 2 (increase). The experimental activation energies were 83 ± 10 (for k 1 ) and 95 ± 5 (for k 2 ) kJ mol −1 . The electronic spectrum of the low reactivity detected intermediate resembled more closely to that of the blue/green reactant than that of the violet reaction product. The low number of protons set free by the complexating hydrogen L-glutamate ligand seems to suggest that some polymerization of the coordinated amino acid (to form a di-or tripeptide) might take place. The available experimental data indicate that the coordination of the organic ligand must be preceded by the breakdown of a strong Cr(III)-H 2 O chemical bond in the slow steps of the mechanism. K E Y W O R D S chromium(III), complexation reaction, kinetics, L-glutamic acid, long-lived intermediate Int J Chem Kinet. 2018;50:591-603. PEREZ-BENITO AND NICOLAS-RIVASES

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Section: Resultsmentioning

confidence: 99%

Kinetics of the chromium(III)/l‐glutamic acid complexation reaction: Formation, decay, and UV‐vis spectrum of a long‐lived intermediate

Perez‐Benito

Nicolas‐Rivases

2018

Int J of Chemical Kinetics

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“…19 Ion-pair high-performance liquid chromatography (IP-HPLC) has proven in many studies to be an effective method for the separation of various oligomers of glycine. 7,[11][12][13][14]16,20,21,34,38,39 In most of these studies, the Gly n product mixtures were limited to n ≤ 6; thus, analytical standards were commercially available. Ohara et al employed the method of Rode and co-workers 21,54 in using HPLC with hexanesulfonate as an ion-pair reagent to measure oligomers up to Gly 6 by UV detection and then used LC with a perfluorinated surfactant to observe Gly 7−10 with detection by MS. 39 Dalai et al produced oligomers up to Gly 6 in their condensations and used IP-HPLC for the primary analysis of the products.…”

Section: T H Imentioning

confidence: 99%

“…The investigation of systems for the efficient synthesis of polypeptides in prebiotically relevant conditions is a major focus of origins-of-life research. Enlivened by Miller’s seminal experiment showing the synthesis of amino acids from a simulated Hadean atmosphere, researchers have studied the condensation of amino acids to form peptides in a variety of prospective prebiotic conditions. − Most proposed prebiotic syntheses of oligopeptides from amino acids can be classified into one or more of the following approaches: (i) catalysis by salts or surfaces at low water activity, − (ii) coupling mediated by stoichiometric reagents, − (iii) strand elongation via acyl-transfer reactions, − (iv) dry-downs and thermal/environmental cycling, ,,− and (v) reactions driven by high-energy sources, like UV light or simulated asteroid impacts (see Figure ). − Glycine is the most popular substrate for these studies because of its presumed prebiotic abundance and its simplicityit lacks a side chain and is achiral; thus, no branched isomers or stereoisomers will form as products. , …”

Section: Introductionmentioning

confidence: 99%

Quantitative Analysis of Glycine Oligomerization by Ion-Pair Chromatography

et al. 2019

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This paper describes a method for the quantitative analysis of mixtures of glycine and its oligomers by ion-pair high-performance liquid chromatography (IP-HPLC), with a particular focus on applications in origins-of-life research. We demonstrate the identification of glycine oligomers (Gly n ) up to 14 residues long—the approximate detectable limit of their solubility in water—and measurement of the concentration of these species in the product mixture of an oligomerization reaction. The molar response factors for higher oligomers of glycine—which are impractical to obtain as pure samples—are extrapolated from direct analysis of pure standards of n = 3–6, which established a clear linear trend. We compare and contrast our method to those in previous reports with respect to accuracy and practicality. While the data reported here are specific to the analysis of oligomers of glycine, the approach should be applicable to the design of methods for the analysis of oligomerization of other amino acids.

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“…Other studies have shown that transition metal ions can affect the reactivity of peptides and thioesters. 4 − 12 Given that the prebiotic ocean was unlikely to have resembled as clean a system as water with a mild pH buffer, 7 , 13 we wished to explore the effect of various dissolved metals on reactions of prospective prebiotic relevance.…”

Section: Introductionmentioning

confidence: 99%

“…The samples in this study were relatively simple solutions in water with a buffer salt (to maintain a constant pH and enable pseudo-first-order kinetics) and an internal standard (to measure accurate concentrations of the thioester). Other studies have shown that transition metal ions can affect the reactivity of peptides and thioesters. − Given that the prebiotic ocean was unlikely to have resembled as clean a system as water with a mild pH buffer, , we wished to explore the effect of various dissolved metals on reactions of prospective prebiotic relevance.…”

Section: Introductionmentioning

confidence: 99%

Removal of Paramagnetic Ions Prior to Analysis of Organic Reactions in Aqueous Solutions by NMR Spectroscopy

et al. 2021

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This article describes a method for improving 1 H NMR spectra of aqueous samples containing paramagnetic metals by precipitation of metal cations with a variety of counteranions. The addition of hydroxide, phosphate, carbonate, and arsenate to solutions of transition metals such as Fe 2+ and Mn 2+ can reduce line broadening and improve the ability of a spectrometer to lock on the signal of deuterium. The method is most effective under strongly alkaline conditions, and care must be taken to observe whether the organic substrates undergo side reactions or are themselves removed from solution upon addition of the precipitating salts. As a demonstration of the practical value of the method, we show that NMR spectroscopy can be used to monitor the transition-metal-mediated hydrolysis of glycylglycine (Gly 2 ).

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Effects of metal ions and pH on the formation and decomposition rates of di- and tri-peptides in aqueous solution

Cited by 10 publications

References 60 publications

Kinetics of the chromium(III)/l‐glutamic acid complexation reaction: Formation, decay, and UV‐vis spectrum of a long‐lived intermediate

Kinetics of the chromium(III)/l‐glutamic acid complexation reaction: Formation, decay, and UV‐vis spectrum of a long‐lived intermediate

Quantitative Analysis of Glycine Oligomerization by Ion-Pair Chromatography

Removal of Paramagnetic Ions Prior to Analysis of Organic Reactions in Aqueous Solutions by NMR Spectroscopy

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