Publications

• Purification and characterization of an alcohol dehydrogenase from the Antarctic psychrophile Moraxella sp. TAE123.

  Tsigos I., Velonia K., Smonou I., Bouriotis V.

  An NAD+-dependent alcohol dehydrogenase (ADH) of the Antarctic psychrophile Moraxella sp. TAE123 was purified to homogeneity with an overall yield of 16.7% and further characterized. The native enzyme had an apparent molecular mass of 240 kDa and consisted of four identical 52-kDa subunits. The pI ... >> More

  An NAD+-dependent alcohol dehydrogenase (ADH) of the Antarctic psychrophile Moraxella sp. TAE123 was purified to homogeneity with an overall yield of 16.7% and further characterized. The native enzyme had an apparent molecular mass of 240 kDa and consisted of four identical 52-kDa subunits. The pI of the enzyme was determined to be 5.5, while its optimum pH is 7.5. The enzyme contained 1 zinc atom/subunit and exhibited a remarkable thermal lability. Moraxella sp. TAE123 ADH exhibited a wide range of substrate specificity similar to its mammalian counterparts and in contrast to other microbial ADHs. It oxidized mainly primary and secondary aliphatic alcohols. The highest reaction rate was observed when ethanol was used as substrate. A gradual decrease in rate was observed by increasing the length and branching of the carbon chain of the alcohol. This enzyme oxidized effectively large bulky alcohols, such as diphenylmethanol. Reduction of aldehydes and ketones was also observed. N-terminal amino acid sequence analysis of the enzyme did not reveal any similarity with the amino termini of all other ADHs, while an unexpected significant similarity was observed with the amino terminal sequence of four prokaryotic aldehyde dehydrogenases. << Less

  Eur. J. Biochem. 254:356-362(1998) [PubMed] [EuropePMC]

  This publication is cited by 8 other entries.

• Bacterial microcompartments: their properties and paradoxes.

  Cheng S., Liu Y., Crowley C.S., Yeates T.O., Bobik T.A.

  Many bacteria conditionally express proteinaceous organelles referred to here as microcompartments (Fig. 1). These microcompartments are thought to be involved in a least seven different metabolic processes and the number is growing. Microcompartments are very large and structurally sophisticated. ... >> More

  Many bacteria conditionally express proteinaceous organelles referred to here as microcompartments (Fig. 1). These microcompartments are thought to be involved in a least seven different metabolic processes and the number is growing. Microcompartments are very large and structurally sophisticated. They are usually about 100-150 nm in cross section and consist of 10,000-20,000 polypeptides of 10-20 types. Their unifying feature is a solid shell constructed from proteins having bacterial microcompartment (BMC) domains. In the examples that have been studied, the microcompartment shell encases sequentially acting metabolic enzymes that catalyze a reaction sequence having a toxic or volatile intermediate product. It is thought that the shell of the microcompartment confines such intermediates, thereby enhancing metabolic efficiency and/or protecting cytoplasmic components. Mechanistically, however, this creates a paradox. How do microcompartments allow enzyme substrates, products and cofactors to pass while confining metabolic intermediates in the absence of a selectively permeable membrane? We suggest that the answer to this paradox may have broad implications with respect to our understanding of the fundamental properties of biological protein sheets including microcompartment shells, S-layers and viral capsids. << Less

  Bioessays 30:1084-1095(2008) [PubMed] [EuropePMC]