Novel Aminomethanesulfonate Buffers for Biological Buffering in the Acidic Range

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Novel Aminomethanesulfonate Buffers for
Biological Buffering in the Acidic Range

• Robert D. Long, Newton P. Hilliard Jr., Daniel
  Dei, Enoch A. Mensah

Paper 432
Patent pending
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Goal

• New buffers for biological systems at pH levels
  well into acidic range (below pH 5.5)
• Needed for acidophilic bacteria studies
• Enzyme/biotech systems at acidic pH
• Good buffers limited usability below
  physiological range
• Metabolic interferences from citrate, borate,
  phosphate, and other systems

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Good Buffers

• Tertiary or secondary amines with alkylsulfonic
  acid attached (varying alkyl chain length)

Ref Good, N. E., et al. Biochemistry 1966, 5(2),
467-477. Good, N. E., and Izawa, S.
Methods Enzymol. 1980, 24, 53-68.
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Desirable Properties (per N. Good)

• midrange pKa
• maximum water solubility and minimum solubility
  in all other solvents
• minimal salt effects
• minimal change in pKa with temperature
• chemically and enzymatically stable
• minimal absorption in visible or UV spectral
  range and
• reasonably easily synthesized.

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Some Lower pH Good Buffers
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Target Compounds
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Routes to Current Good Buffers
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Synthesis of Aminomethanesulfonates
Ref Johnson, T.B. JACS 1941, 63, 1571-1572.
Raschig, F. Prahl, W., Ann. 1926, 448, 265.
Gilbert, E. E., Sulfonation and Related
Reactions Interscience NY, 1965
Ref Knoevenagel, E., Ber. 1904, 37, 4087.
Neelakantan Hartung, JOC 1959, 24, 1943.
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Synthesis of Other Targets
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Ionization of Aminoalkylsulfonates
MMS morpholinomethanesulfonic acid
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Crystallography of MMS
Sodium salt form (no protonation)
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Crystallography of HEPMS
Note Zwitterion
Protonated amine
Sulfonate anion
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pKa Comparison
pKa2 value
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Initial Growth Studies
E. coli strain HB101 at pH 7.2 and 37ºC for 18
hours
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In-progress Biological Testing

• Halothiobacillus neapolitanus at acidic pH
• E. coli H. neapolitanus transformation
  efficiency
• Enzyme reactions (food technology/ glycosidases)
  in the acidic range

Preliminary testing shows increased
efficiency/activity in all three areas with MMS
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Acknowledgements

• BRIN/INBRe (NIH-NCRR P20-016840) (Infrastructure
  grant)
• Dr. Newton Hilliard (Biochemistry)
• Grad students
• Enoch Mensah
• Daniel Dei
• Science Technology Corp. (STC) at Univ. of New
  Mexico (Patent pending)
• (For more info contact robert.long_at_enmu.edu or
  ssheehan_at_unm.edu)