Purification and characterization of 4-<i>N</i>-trimethylamino-1-butanol dehydrogenase from <i>Fusarium merismoides</i> var. <i>acetilereum</i>

<p>From investigation of 60 filamentous fungi, we identified <i>Fusarium merismoides</i> var. <i>acetilereum</i>, which uses 4-<i>N</i>-trimethylamino-1-butanol (TMA-butanol) as the sole source of carbon and nitrogen. The fungus produced NAD⁺-dependent TMA-butanol dehydrogenase (DH) when it was cultivated in medium containing TMA-butanol. The enzyme showed molecular mass of 40 kDa by SDS–PAGE and 160 kDa by gel filtration, suggesting that it is a homotetramer. TMA-butanol DH is stable at pH 7.5–9.0. It exhibits moderate stability with respect to temperature (up to 30 °C). Additionally, it has optimum activity at 45 °C and at pH 9.5. The enzyme has broad specificity to various alkyl alcohols and amino alkyl alcohols, and the carbon chains of which are longer than butanol. Moreover, the activity is strongly inhibited by oxidizing agents, carbonyl and thiol modulators, and chelating agents. This report is the first study examining TMA-butanol DH from eukaryotic microbes.</p> <p>Having broad substrate specificity, 4-<i>N</i>-trimethylamino-1-butanol dehydrogenase (TMA-butanol DH) from <i>Fusarium merismoides</i> var. <i>acetilereum</i> was purified and characterized.</p

Purification, gene cloning, and characterization of γ-butyrobetainyl CoA synthetase from <i>Agrobacterium</i> sp. 525a

<p>The report is the first of purification, overproduction, and characterization of a unique γ-butyrobetainyl CoA synthetase from soil-isolated <i>Agrobacterium</i> sp. 525a. The primary structure of the enzyme shares 70–95% identity with those of ATP-dependent microbial acyl-CoA synthetases of the Rhizobiaceae family. As distinctive characteristics of the enzyme of this study, ADP was released in the catalytic reaction process, whereas many acyl CoA synthetases are annotated as an AMP-forming enzyme. The apparent <i>K</i>_m values for γ-butyrobetaine, CoA, and ATP were, respectively, 0.69, 0.02, and 0.24 mM.</p> <p>γ-Butyrobetainyl CoA synthetase, the first enzyme of the β-oxidation-like pathway involving γ-butyrobetaine degradation, was reported in this study.</p