Chiral methyl groups: small is beautiful

Floss, Heinz G.; Lee, Sungsook

doi:10.1021/ar00027a007

Cited by 61 publications

(34 citation statements)

References 52 publications

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“…The preparation of asymmetric methyl groups has al ong and rich history in organic chemistry [101][102][103][104] with recently identified applicationsi nf undamentalp hysics for measuring parity-violating energyd ifferences between enanteomers. [105] Theu se of ac hiral methyl group CHDT in MOR could lead to chiral molecules that can be directly laser cooled:SrOCHDT and CaOCHDT.…”

Section: Laser-cooled Chiral Speciesmentioning

confidence: 99%

“…However,o ur proposed optical cycling schemed elivering $10 3 scattered photons per molecule opens ap ath towards the use of coherent opticalb ichromatic forces (BCF) for rapid deceleration of MOR originating from aC BGB to near the capture velocity of am olecular MOT, v cap $10 ms À1 . [101] Following successful experimental resultsf or atomic beams, there has been different new schemes proposed forefficient laser slowing of diatomic molecules on both electronic [111][112][113] and vibrational transitions. [114] While we surmise that these techniques could be applied to MOR species, detaileds imulations of the bichromatic force in complex multilevel systems (e.g.…”

Section: Coherent Slowingmentioning

confidence: 99%

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Proposal for Laser Cooling of Complex Polyatomic Molecules

et al. 2016

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An experimentally feasible strategy for direct laser cooling of polyatomic molecules with six or more atoms is presented. Our approach relies on the attachment of a metal atom to a complex molecule, where it acts as an active photon cycling site. We describe a laser cooling scheme for alkaline earth monoalkoxide free radicals taking advantage of the phase space compression of a cryogenic buffer-gas beam. Possible applications are presented including laser cooling of chiral molecules and slowing of molecular beams using coherent photon processes.

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Section: Laser-cooled Chiral Speciesmentioning

confidence: 99%

Section: Coherent Slowingmentioning

confidence: 99%

Proposal for Laser Cooling of Complex Polyatomic Molecules

et al. 2016

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“…The stereochemical course of side chain attachment was shown to be inversion through the incorporation of methionine stereospecifically deuterated at C-4 (13). This configurational outcome parallels the stereochemistry of addition of the 3-aminopropyl moiety derived from decarboxylated S-adenosylmethionine (AdoMet) 1 operative in the biosynthesis of the polyamines (14 -16), as well as more conventional methyltransferases (17,18), suggesting a role for AdoMet in nocardicin A biosynthesis in vivo. This postulate was borne out in preliminary cell-free studies in which an efficient, time-dependent conversion from nocardicin E (5) to nocardicin A in the presence of AdoMet was demonstrated (19).…”

mentioning

confidence: 82%

Purification, Characterization, and Cloning of an S-Adenosylmethionine-dependent 3-Amino-3-carboxypropyltransferase in Nocardicin Biosynthesis

Reeve

Breazeale

Townsend

1998

Journal of Biological Chemistry

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S-Adenosylmethionine:nocardicin 3-amino-3-carboxypropyltransferase catalyzes the biosynthetically rare transfer of the 3-amino-3-carboxypropyl moiety from S-adenosylmethionine to a phenolic site in the ␤-lactam substrates nocardicin E, F, and G, a late step of the biosynthesis of the monocyclic ␤-lactam antibiotic nocardicin A. Whereas a number of conventional methods were ineffective in purifying the transferase, it was successfully obtained by two complementary affinity chromatography steps that took advantage of the two substrate-two product reaction scheme. S-Adenosylhomocysteine-agarose selected enzymes that utilize S-adenosylmethionine, and a second column, nocardicin Aagarose, specifically bound the desired transferase to yield the enzyme as a single band of 38 kDa on a silverstained SDS-polyacrylamide gel. The transferase is active as a monomer and exhibits sequential kinetics. Further kinetic characterization of this protein is described and its role in the biosynthesis of nocardicin A discussed. The gene encoding this transferase was cloned from a sublibrary of Nocardia uniformis DNA. Translation gave a protein of deduced mass 32,386 Da which showed weak homology to small molecule methyltransferases. However, three correctly disposed signature motifs characteristic of these enzymes were observed.

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“…The chirality of the methyl group was then determined by the enzymatic methods of Arigoni [101] and Cornforth [102]. Hence, it was found that the majority (if not all) of AdoMet-dependent MTases catalyze methyl group transfer with an inversion of configuration which is consistent with a single transfer step and an S N 2-type transition state [103].…”

Section: The Biosynthesis and Metabolism Of Adometmentioning

confidence: 99%

S‐Adenosyl‐L‐Methionine and Related Compounds

Dalhoff¹,

Weinhold

2008

Modified Nucleosides

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The sulfonium compound S-adenosyl-L-methionine (AdoMet, also known as SAM or SAMe, 1) is one of the most versatile biomolecules in nature and one of the most widely used enzyme substrates, second perhaps only to adenosine triphosphate (ATP) (Schemes 9.1 and 9.2). AdoMet (1) may be found in all phyla of life, and is one of the molecules crucial for the existence of living organisms. First identified by Cantoni in 1953 [1, 2] as the active methyl donor formed from L-methionine and ATP, AdoMet (1) proved to be not only the major methyl donor in nature but also to be involved in many other metabolic reactions [3,4]. The versatility of the cofactor is based on the reactivity of the pivotal sulfonium center, which activates the adjacent carbon atoms for nucleophilic attack, deprotonation, and radical formation. This leads to a unique cofactor in which all constituents are used in biochemical reactions. The group transfer reactions result in the release of one of three different thioether products which are more stable than the sulfonium compound, and thereby providing the driving force for these enzyme-catalyzed reactions. These highly preferable thermodynamics of AdoMet-dependent transfer reactions result in a strong preference for this cofactor compared, for example, to other methyl donors such as N5-methyltetrahydrofolate. Due to the electron lone pair in addition to the three different substituents, the sulfonium group is chiral, and the naturally occurring AdoMet (1) is S-configured at sulfur [5].Many other naturally occurring alkylated thioadenosines are derived from AdoMet (1) such as S-adenosyl-L-homocysteine (AdoHcy, also called SAH, 2) and 5 0 -deoxy-5 0 -methylthioadenosine (MTA, 3) (Scheme 9.3), although these compounds and their related 5 0 -thioethers are beyond the scope of this chapter. AdoMet (1) and its derivatives are involved in key metabolic reactions, cell cycle regulation and the storage of epigenetic information, which makes them not only highly interesting for studying biological pathways but also as in-vitro or in-vivo biochemical tools and candidates for diagnostics and therapeutics.

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Chiral methyl groups: small is beautiful

Cited by 61 publications

References 52 publications

Proposal for Laser Cooling of Complex Polyatomic Molecules

Proposal for Laser Cooling of Complex Polyatomic Molecules

Purification, Characterization, and Cloning of an S-Adenosylmethionine-dependent 3-Amino-3-carboxypropyltransferase in Nocardicin Biosynthesis

S‐Adenosyl‐L‐Methionine and Related Compounds

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