Hydroxylamine anion ? an effective ?-nucleophile in acyl transfer reactions

Simanenko, Yu. S.; Popov, A. F.; Prokop’eva, T. M.; Savëlova, V. A.; Belousova, І. A.

doi:10.1007/bf00530586

Cited by 5 publications

(6 citation statements)

References 5 publications

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“…HA is an α-nucleophile that intercepts between amide-ester equilibrium and induces N-cleavage. It enhances the nucleophilicity of residues that leads to N-cleavage [ 84 , 85 ]. A pseudo-first-order fit for the HA-induced reaction time course with the equation, Y = Y0 + (Plateau-Y0) * (1-exp(-K*x)) was obtained ( Figure 5 ).…”

Section: Resultsmentioning

confidence: 99%

SufB intein splicing in Mycobacterium tuberculosis is influenced by two remote conserved N-extein histidines

et al. 2022

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Inteins are auto-processing domains that implement a multistep biochemical reaction termed protein splicing, marked by cleavage and formation of peptide bonds. They excise from a precursor protein, generating a functional protein via covalent bonding of flanking exteins. We report the kinetic study of splicing and cleavage reaction in [Fe–S] cluster assembly protein SufB from Mycobacterium tuberculosis (Mtu). Although it follows a canonical intein splicing pathway, distinct features are added by extein residues present in the active site. Sequence analysis identified two conserved histidines in the N-extein region; His-5 and His-38. Kinetic analyses of His-5Ala and His-38Ala SufB mutants exhibited significant reductions in splicing and cleavage rates relative to the SufB wildtype (WT) precursor protein. Structural analysis and molecular dynamics (MD) simulations suggested that Mtu SufB displays a unique mechanism where two remote histidines work concurrently to facilitate N-terminal cleavage reaction. His-38 is stabilized by the solvent-exposed His-5, and can impact N–S acyl shift by direct interaction with the catalytic Cys1. Development of inteins as biotechnological tools or as pathogen-specific novel antimicrobial targets requires a more complete understanding of such unexpected roles of conserved extein residues in protein splicing.

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Section: Resultsmentioning

confidence: 99%

SufB intein splicing in Mycobacterium tuberculosis is influenced by two remote conserved N-extein histidines

et al. 2022

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“…HA is an alpha nucleophile that intercepts between amide-ester equilibrium and induces N-cleavage. It enhances the nucleophilicity of residues that leads to N-cleavage (73, 74). The mutation effect on HA-induced N-cleavage reaction was similar to what is observed in presence of TCEP.…”

Section: Resultsmentioning

confidence: 99%

“…HA is an alpha nucleophile that intercepts between amide-ester equilibrium and induces N-cleavage. It enhances the nucleophilicity of residues that leads to N-cleavage (84, 85). A pseudo-first-order fit for the HA-induced reaction time course with the equation, Y=Y0 +(Plateau-Y0) *(1-exp(-K*x)) was obtained (Figure 5).…”

Section: Resultsmentioning

confidence: 99%

SufB intein splicing inMycobacterium tuberculosisis influenced by two remote conserved N-extein Histidines

Panda

Nanda

Sahu

et al. 2021

Preprint

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Inteins are auto-processing domains that implement a multi-step biochemical reaction termed protein splicing, marked by cleavage and formation of peptide bonds. They excise from a precursor protein, generating a functional protein via covalent bonding of flanking exteins. We report the kinetic study of splicing and cleavage reaction in a [Fe-S] cluster assembly protein SufB from Mycobacterium tuberculosis. Although it follows a canonical intein splicing pathway, distinct features are added by extein residues present in the active site. Sequence analysis identified two conserved histidines in the N-extein region; His-5 and His-38. Kinetic analyses of His-5Ala and His-38Ala SufB mutants exhibited significant reductions in splicing and cleavage rates relative to the SufB wild-type precursor protein. Structural analysis and molecular dynamics simulations suggested that Mtu SufB displays a unique mechanism where two remote histidines work concurrently to facilitate N- cleavage reaction. His-5, which is exposed outside, because of the random push of water molecules forces His-38 towards the N-cleavage site. Thus, His-5 stabilizes the position of His-38 which in turn activates N-S acyl shift via direct interaction with catalytic Cys1. Understanding intein~extein partnership in an essential mycobacterial protein may diversify into intein-based applied research along with the development of pathogen-specific novel antimicrobials.

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“…25,26 On the other hand, this unfavorable isomerization of hydrazine and hydrogen peroxide should result in less reactivity. We wonder if similar species like hydrazine and hydrogen peroxide could also present this property.…”

Section: Resultsmentioning

confidence: 99%

The role of ammonia oxide in the reaction of hydroxylamine with carboxylic esters

2015

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Theoretical calculations indicate that hydroxylamine can exist in both neutral and zwitterionic (ammonia oxide) forms in aqueous solution, the former being 3.5 kcal mol(-1) more stable. In this report, we have studied the reaction mechanism of hydroxylamine with phenyl acetate and analyzed the role of the zwitterionic isomer. We have observed that the main reaction pathway takes place through the zwitterionic form with a concerted mechanism, not involving the classical tetrahedral intermediate. Attack by the nitrogen atom (via neutral isomer) has a minor contribution and it is also a concerted process. The activation free energy barriers in aqueous solution were calculated at the MP4/TZVPP + diff level for gas phase energies, CPCM for optimization and frequencies, and through single point calculation of the solvation free energy using the SM8 method. Our theoretically predicted barriers are 20.8 and 23.8 kcal mol(-1) for O and N attack, respectively, in very good agreement with the experimental values of 20.4 and 22.3 kcal mol(-1), respectively. Our results support the view that hydroxylamine is a very special nucleophile and the reactivity of this functional group should be further investigated.

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Hydroxylamine anion ? an effective ?-nucleophile in acyl transfer reactions

Cited by 5 publications

References 5 publications

SufB intein splicing in Mycobacterium tuberculosis is influenced by two remote conserved N-extein histidines

SufB intein splicing in Mycobacterium tuberculosis is influenced by two remote conserved N-extein histidines

SufB intein splicing inMycobacterium tuberculosisis influenced by two remote conserved N-extein Histidines

The role of ammonia oxide in the reaction of hydroxylamine with carboxylic esters

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