D-Methionine

Technical Specifications

Product Description & Scientific Applications

D-Methionine ((R)-methionine, H-D-Met-OH) is the unnatural enantiomer of methionine. It has the same melting point and solubility as the L form. Enzymes, transporters and cell-wall enzymes tell the two apart, and only L-methionine is used in ribosomal protein synthesis. Enantiomeric identity is checked by specific rotation: −23 to −25° at c = 4 in 1:1 hydrochloric acid.

Applications and Reactions

• Peptidoglycan and cell-wall remodelling: Bacteria incorporate non-canonical D-amino acids, D-methionine among them, into the fifth position of peptidoglycan muropeptides. It probes cell-wall editing and the enzymes that perform it.
• Biofilm research: A 2010 report found D-methionine, with D-leucine, D-tyrosine and D-tryptophan, in a Bacillus subtilis factor that acted against biofilms at nanomolar concentrations. The mechanism is disputed. Later work attributed the effect to interference with protein synthesis rather than to matrix disassembly, and a separate study found no inhibition of Staphylococcus aureus biofilms.
• Spore germination: D-methionine does not trigger germination of Clostridium sporogenes or C. botulinum spores. It blocks the germination that L-methionine induces, and so probes germinant receptor specificity.
• Otoprotection: Studied against cisplatin, aminoglycoside and noise-induced cochlear damage. Cochlear oxidative state is followed through superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and malondialdehyde. Rescue dosing reduced permanent threshold shift for steady-state noise at every dose, time and frequency tested, but did not reduce temporary threshold shift.
• Radioprotection: It protected non-transformed human cells in culture from radiation-induced death, and protected tumour cells less. That difference is the basis of the mucositis work.
• Tumour imaging: Radiolabelled D-methionine reached roughly three times the tumour radioactivity of the L-isomer in Ehrlich solid tumour. Both labelled isomers serve as positron emission tomography tracers for brain tumours.
• Biocatalysis and transport: A four-enzyme cascade converts D-methionine to L-methionine. The bacterial periplasmic binding protein MetQ binds both isomers, so the pair tests stereospecificity in transport studies.

Shipping Destinations

• EU & UK: Priority delivery, 2–5 business days.
• United States (DDP): 3–7 business days, duties and taxes prepaid.
• EFTA Countries (DDP): 3–7 business days, duties and taxes prepaid.
• Worldwide: 7–14 business days, selected locations.