Ein-Atom-Substitution in Peptiden: Bildung eines photoschaltbaren Elements im Peptidrückgrat durch Thioxylierung

Frank, Robert M.; Jakob, Mario; Thunecke, Frank; Fischer, Gunter; Schutkowski, Mike

doi:10.1002/(sici)1521-3757(20000317)112:6<1163::aid-ange1163>3.0.co;2-h

Cited by 16 publications

(3 citation statements)

References 25 publications

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“…Annealing of matrices containing the cis conformer at temperatures up to 40 K did not result in a rearrangement to trans, which suggests that the barrier for this isomerization is too high to be surpassed under the conditions of matrix isolation. [15][16][17] The photoisomerization of N-methylthioacetamide (NMTAA) in different matrices, for instance, has been studied by Ataka et al, [18] who reported reversible trans-cis isomerization in N 2 and Ar matrices. [8] It is well-documented that the conformational isomerization of amides and thioamides can be induced by n-p* and p-p* excitations.…”

Section: Introductionmentioning

confidence: 99%

Photochemistry of N‐Methylformamide: Matrix Isolation and Nonadiabatic Dynamics

et al. 2012

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The photochemistry of N-methylformamide (MF) is elucidated by investigating its photodissociation products generated by UV irradiation (248 nm) in an argon matrix (10 K). We find that, starting from trans-MF, prolonged irradiation produces cis-MF, CH3NH2 and CO fragments as major products. Another photoproduct is identified as methylformimidic acid (FIA). Nonadiabatic dynamics simulations starting from both MF conformers revealed that the internal conversion occurs within 1 ps through a C-N dissociation channel. The major product is a weakly bound complex between CH3NH and HCO radicals. This complex owes its existence to the cage effect of the matrix which allows for H-transfer reactions and recombination. By identifying the primary photoisomerization and photodissociation pathways of MF, we gain new insights into the photochemistry of peptide bonds in general, which is a prerequisite for a better understanding of the effect of UV irradiation on living systems.

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Section: Introductionmentioning

confidence: 99%

Photochemistry of N‐Methylformamide: Matrix Isolation and Nonadiabatic Dynamics

et al. 2012

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“…We have been developing a new approach to the peptide bond as a photoresponsive element of a protein that utilizes features of the nearisosteric thioxopeptide bond (sC(dS)sNRs; R ) H, alkyl) substitution. [21][22][23] The process of photoisomerization of short thioxopeptides is completed within the picosecond time scale at a high quantum yield and does not exhibit a more prolonged reaction time for a longer peptide chain. 24,25 Biologically, the O/S exchange causes minor effects as long as a bioreaction does not directly involve the respective amide carbonyl group.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, fast re-equilibration rates prevent the photoinduced cis population from applying isomer-specific effects on a coupled reaction. We have been developing a new approach to the peptide bond as a photoresponsive element of a protein that utilizes features of the near-isosteric thioxopeptide bond (C(S)NR; R = H, alkyl) substitution. − The process of photoisomerization of short thioxopeptides is completed within the picosecond time scale at a high quantum yield and does not exhibit a more prolonged reaction time for a longer peptide chain. , Biologically, the O/S exchange causes minor effects as long as a bioreaction does not directly involve the respective amide carbonyl group. In particular, it does not greatly affect secondary structure formation, and the bioactivity of the thioxopeptide derivative of ligands was found to be similar to that of the oxopeptide congener. − However, the lack of methods is evident for the site-specific thioxylation of a mature polypeptide chain and the chemical synthesis of an enzyme thioxylated at a predefined position.…”

Section: Introductionmentioning

confidence: 99%

A Nearly Isosteric Photosensitive Amide-Backbone Substitution Allows Enzyme Activity Switching in Ribonuclease S

et al. 2007

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psi[CS-NH]4-RNase S, a site specific modified version of RNase S obtained by thioxylation (O/S exchange) at the Ala4-Ala5- peptide bond, was used to evaluate the impact of protein backbone photoswitching on bioactivity. psi[CS-NH](4)-RNase S was yielded by recombination of the S-protein and the respective chemically synthesized thioxylated S-peptide derivative. Comparison with RNase S revealed similar thermodynamic stability of the complex and an unperturbed enzymatic activity toward cytidine 2',3'-cyclic monophosphate (cCMP). Reversible photoisomerization with a highly increased cis/trans isomer ratio of the thioxopeptide bond of psi[CS-NH](4)-RNase S in the photostationary state occurred under UV irradiation conditions (254 nm). The slow thermal reisomerization (t(1/2) = 180 s) permitted us to determine the enzymatic activity of cis psi[CS-NH](4)-RNase S by measurement of initial rates of cCMP hydrolysis. Despite thermodynamic stability of cis psi[CS-NH](4)-RNase S, its enzymatic activity is completely abolished but recovers after reisomerization. We conclude that the thioxopeptide bond modified polypeptide backbone represents a versatile probe for site-directed photoswitching of proteins.

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Closthioamide: An Unprecedented Polythioamide Antibiotic from the Strictly Anaerobic Bacterium Clostridium cellulolyticum

Lincke¹,

Behnken²,

Ishida³

et al. 2010

Angewandte Chemie

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Schwefel für die sauerstofffreie Welt: Closthioamid (1), der einzige bekannte sekundäre Metabolit eines streng anaeroben Bakteriums, wurde aus anaerobem Clostridium cellulolyticum (siehe SEM‐Bild) nach Induktion der Biosynthese mit einem wässrigen Bodenextrakt isoliert. Dieser neue Typ eines symmetrischen Naturstoffs, in dem alle Bausteine durch Thioamideinheiten verknüpft sind, hemmt das Wachstum multiresistenter Staphylokokken.

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Ein-Atom-Substitution in Peptiden: Bildung eines photoschaltbaren Elements im Peptidrückgrat durch Thioxylierung

Cited by 16 publications

References 25 publications

Photochemistry of N‐Methylformamide: Matrix Isolation and Nonadiabatic Dynamics

Photochemistry of N‐Methylformamide: Matrix Isolation and Nonadiabatic Dynamics

A Nearly Isosteric Photosensitive Amide-Backbone Substitution Allows Enzyme Activity Switching in Ribonuclease S

Closthioamide: An Unprecedented Polythioamide Antibiotic from the Strictly Anaerobic Bacterium Clostridium cellulolyticum

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