Aromatic alcohol dehydrogenase from potato tubers

The purification of NADP specific aromatic alcohol dehydrogenase is reported. The properties of the enzyme suggest that it should be classified as E.C. 1.1.1.2. Kinetic constants for a number of substrates are reported. The relative rates of reaction of a variety of substituted benzaldehydes have been found to correlate with Hammett's sigma values yielding a biphasic relationship. The physiological significance of the enzyme is briefly discussed.     

Aliphatic alcohol dehydrogenase from potato tubers

Potato tubers are shown to contain at least 3 alcohol dehydrogenases, one active with NAD and aliphatic alcohols, one active with NADP and terpene alcohols and one active with NADP and aromatic alcohols. The purification of the aliphatic alcohol dehydrogenase is described and its activity with a wide range of substrates is reported. On the basis of substrate specificity, the enzyme is shown to resemble yeast alcohol dehydrogenase rather than liver alcohol dehydrogenase. The enzyme shows high activity with and high affinity for ethanol, activity and affinity decline as the chain length is increased from ethanol to butanol, but a further increase in chain length leads to increased affinity for the alcohol. The physiological significance of the results is briefly discussed.     

Nucleotide sequence of two cDNAs encoding fucoxanthin chlorophyll a/c proteins in the diatom Odontella sinensis

Two cDNA clones encoding fucoxanthin chlorophyll a/c-binding proteins (FCP) in the diatom Odontella sinensis have been cloned and sequenced. The derived amino acid sequences of both clones are identical, comparison of the corresponding nucleic acids reveals differences only in the third codon position, suggesting a recent gene duplication. The derived proteins are similar to the chlorophyll a/b-binding proteins of higher plants. The presequences for plastid import resemble signal sequences for cotranslational import rather than transit peptides of higher plants. They are very similar to the presequences of FCP proteins in the diatom Phaeodactylum, but different from the presequences of the -subunit of CF₀CF₁ of Odontella and the peridinin chlorophyll a binding proteins (PCP) of the dinoflagellate Symbiodinium.Abbreviations CAB chlorophyll a/b-binding protein - FCP fucoxanthin chlorophyll a/c-binding protein - fcp the respective FCP genes - LHC light-harvesting complex - PCP peridinin chlorophyll a-binding protein - PAGE polyacrylamide gel electrophoresis - SDS sodium dodecyl sulfate