Dehydroamino Acids, α-Hydroxy-α-amino Acids and α-Mercapto-α-amino Acids

Schmidt, Ulrich; Häusler, Johannes; Öhler, Elisabeth; Poisel, Hans

doi:10.1007/978-3-7091-8545-2_3

Cited by 36 publications

(12 citation statements)

References 310 publications

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“…The dehydro residues of nisin, in which the double bond is conjugated with the peptide carbonyl ( Fig. 1) are typical Michael acceptors, which should react readily with mercaptans and other good nucleophiles (4, 10,13,15,35,41). Although the reaction of nisin with mercaptans has been demonstrated, no kinetic information is available.…”

Section: Resultsmentioning

confidence: 99%

Some chemical and physical properties of nisin, a small-protein antibiotic produced by Lactococcus lactis

Liu

Hansen

1990

Appl Environ Microbiol

312

136

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Nisin is a small gene-encoded antimicrobial protein produced by Lactococcus lactis that contains unusual dehydroalanine and dehydrobutyrine residues. The reactivity of these residues toward nucleophiles was explored by reacting nisin with a variety of mercaptans. The kinetics of reaction with 2-mercaptoethanesulfonate and thioglycolate indicated that the reaction pathway includes a binding step. Reaction of nisin at high pH resulted in the formation of multimeric products, apparently as a result of intramolecular and intermolecular reactions between nucleophilic groups and the dehydro residues. One of the nucleophiles had a PKa of about 9.8. The unique vinyl protons of the dehydro residues that give readily identifiable proton nuclear magnetic resonances were used to observe the addition of nucleophiles to the dehydro moiety. After reaction with nucleophiles, nisin lost its antibiotic activity and no longer showed the dehydro resonances, indicating that the dehydro groups had been modified. The effect of pH on the solubility of nisin was determined; the solubility was quite high at low pH (57 mg/ml at pH 2) and was much lower at high pH (0.25 mg/ml at pH 8 to 12), as measured before significant pH-induced chemical modification had occurred. High-performance liquid chromatography on a C18 column was an effective technique for separating unmodified nisin from its reaction products. The cyanogen bromide cleavage products of nisin were about 90% less active toward inhibition of bacterial spore outgrowth than was native nisin. These results are consistent with earlier observations, which suggested that the dehydro residues of nisin have a role in the mechanism of antibiotic action, in which they act as electrophilic Michael acceptors toward nucleophiles in the cellular target.

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Section: Resultsmentioning

confidence: 99%

Some chemical and physical properties of nisin, a small-protein antibiotic produced by Lactococcus lactis

Liu

Hansen

1990

Appl Environ Microbiol

312

136

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“…α , β ‐Unsaturated (didehydro)‐ α ‐amino acids (Figure ), typically represented by the notation ΔAAs, are often reported to occur in natural peptides of microbial origin and, to a limited extent, in proteins (e.g. in the bioluminescent proteins) as well . In particular, they characterize the well‐studied family of lantibiotics, i.e.…”

Section: Cαβ‐didehydro‐α‐amino Acid‐containing Peptidesmentioning

confidence: 99%

Handedness preference and switching of peptide helices. Part II: Helices based on noncodedα‐amino acids

Crisma¹,

Zotti

Formaggio

et al. 2015

Journal of Peptide Science

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In this second part of our review article on the preferred screw sense and interconversion of peptide helices, we discuss the most significant computational and experimental data published on helices formed by the most extensively investigated categories of noncoded α-amino acids. They are as follows: (i) N-alkylated Gly residues (peptoids), (ii) C(α) -alkylated α-amino acids, (iii) C(α,β) -sp(2) configurated α-amino acids, and (iv) combinations of residues of types (ii) and (iii). With confidence, the large body of interesting papers examined and classified in this editorial effort will stimulate the development of helical peptides in many diverse areas of biosciences and nanosciences.

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“…(iii) And finally, the presence of an et,~-unsaturated a-amino acid unit in the structure adds significant difficulties to the preparation of the linear precursor. The presence of the double bond in a dehydro amino acid dramatically reduces both the reactivity of the carboxylic acid and the nucleophilicity of the amine function [7]. This suggests that the double bond should be introduced into the molecule after peptide bond formation.…”

Section: Introductionmentioning

confidence: 99%

Analogues of tentoxin: Tools for mechanistic investigations

et al. 1997

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SUMMARYTentoxin [cyclo-(MeAla I -Leu2-MeAPhe3-Gly 4] is a metabolite isolated from a phytopathogenic fungus Alternaria alternata, which induces chlorosis of many plants. This potential natural herbicide binds specifically to the soluble part CF 1 of the chloroplastic coupling factor, which is a proton ATP-synthase. The effect of the toxin is concentration dependent: at low concentration it is a powerful inhibitor, while at higher concentration, it stimulates the enzyme. We synthesized tentoxin and we designed new analogues in order to vary the hydrophobicity on the side chain and to study the structure activity relationships. Comparative activities suggest that it is possible to separate inhibitory and activating effects using tentoxin analogues, showing some evidence for the existence of two binding sites with different affinity constant.

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Dehydroamino Acids, α-Hydroxy-α-amino Acids and α-Mercapto-α-amino Acids

Cited by 36 publications

References 310 publications

Some chemical and physical properties of nisin, a small-protein antibiotic produced by Lactococcus lactis

Some chemical and physical properties of nisin, a small-protein antibiotic produced by Lactococcus lactis

Handedness preference and switching of peptide helices. Part II: Helices based on noncodedα‐amino acids

Analogues of tentoxin: Tools for mechanistic investigations

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