Recently we found that firefly luciferase is a bifunctional enzyme, catalyzing not only the luminescence reaction but also long-chain fatty acyl-CoA synthesis. Further, the gene product of CG6178 (CG6178), an ortholog of firefly luciferase in Drosophila melanogaster, was found to be a long-chain fatty acyl-CoA synthetase and dose not function as a luciferase. We investigated the substrate specificities of firefly luciferase and CG6178 as an acyl-CoA synthetase utilizing a series of carboxylic acids. The results indicate that these enzymes synthesize acyl-CoA efficiently from various saturated medium-chain fatty acids. Lauric acid is the most suitable substrate for these enzymes, and the product of lauroyl CoA was identified with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Phylogenetic analysis indicated that firefly luciferase and CG6178 genes belong to the group of plant 4-coumarate:CoA ligases, and not to the group of medium-and long-chain fatty acyl-CoA synthetases in mammals. These results suggest that insects have a novel type of fatty acyl-CoA synthetase.

Bi 2 Sr 2 CaCu 2 O 8+δ (Bi2212) single-crystal whiskers were grown by annealing sintered Te-doped Bi–Sr–Ca–Cu–O precursors that had not passed through a melt-quenched glassy state, a process that is known well at this time. The optimum nominal composition of precursors is Ca-rich Bi2Sr2Ca2Cu2Te0.5Ox with a Te content of 0.5. The whiskers contain no Te element. The precursors are mainly composed of Bi2212 and (SrCa)3TeO6 (STO) phases. The STO or the element Te acts as a catalyst in enhancing whisker growth. The critical current (Ic) with a multibranched structure of the current–voltage characteristics due to the intrinsic Josephson junctions along the c axis is quite uniform, showing that the whiskers are homogeneous and of good quality.

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Single-crystal whiskers of YBa2Cu3Ox (Y-123) phase with a length of about 2.5 mm were grown from sintered precursor powders with a nominal composition of Y1Ba2Cu3Te0.5Ca1.0Ox. Electron probe microanalysis analyses showed that the whiskers contain Ca but no Te with a composition of (Y0.86Ca0.14)Ba2Cu3Ox in which 14%Y is substituted by Ca. The precursor powder is composed of Ca-doped Y-123 and (BaCa)3TeO6 phases. The presence of the (BaCa)3TeO6 plays an important role in enhancing the growth of the whiskers. The whiskers show a critical temperature Tc of about 83 K and a critical current density, Jc of 4.4×104 A/cm2 at 82 K and self-field along the c axis. The whiskers exhibit interesting intrinsic Josephson effects along the c axis.

Three homologous genes of firefly luciferase were cloned from the non-luminous beetle Tenebrio molitor. Three gene products for homologues, TmLL-1, TmLL-2 and TmLL-3, showed fatty acyl-coenzyme A (acyl-CoA) synthetic activity, but not luciferase activity with firefly luciferin. The transcripts were detected through the developmental stages in T. molitor. These results suggested that firefly luciferase was evolved from a fatty acyl-coenzyme A synthetase by gene duplications in the insect.