Okada Shigeru, Devarenne Timothy P, Murakami Masahiro, Abe Hiroki, Chappell Joseph
Laboratory of Marine Biochemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
Arch Biochem Biophys. 2004 Feb 1;422(1):110-8. doi: 10.1016/j.abb.2003.12.004.
The extracellular matrix of the alga Botryococcus braunii, Race B, consists mainly of botryococcenes, which have potential as a hydrocarbon fuel. Botryococcenes are structurally similar to squalene raising the possibility of a common enzyme for the biosynthesis of both. While B. braunii squalene synthase (SS) enzyme activity has been documented, botryococcene synthase (BS) enzyme activity has not been. In the current study, an assay for BS activity has been developed and used to show that many of the assay conditions for BS enzyme activity are similar to those of SS. However, SS enzyme activity is stimulated by Tween 80 while BS enzyme activity is inhibited. Moreover, BS enzyme activity was correlated with the accumulation of botryococcenes during a B. braunii culture growth cycle, which was distinctly different from the profile of SS enzyme activity. While the current results indicate a conservation of enzymological features amongst the BS and SS enzymes, raising the possibility of one enzyme capable of catalyzing both activities, they are also consistent with these two activities arising from separate and distinct enzymes.
布朗葡萄藻B族的细胞外基质主要由具有作为碳氢燃料潜力的葡萄藻烯组成。葡萄藻烯在结构上与角鲨烯相似，这增加了两者生物合成存在共同酶的可能性。虽然已经记录了布朗葡萄藻角鲨烯合酶（SS）的酶活性，但葡萄藻烯合酶（BS）的酶活性尚未被记录。在当前的研究中，已开发出一种用于BS活性的测定方法，并用于表明BS酶活性的许多测定条件与SS的相似。然而，SS酶活性受到吐温80的刺激，而BS酶活性受到抑制。此外，在布朗葡萄藻培养生长周期中，BS酶活性与葡萄藻烯的积累相关，这与SS酶活性的情况明显不同。虽然目前的结果表明BS和SS酶之间存在酶学特征的保守性，增加了一种酶能够催化两种活性的可能性，但它们也与这两种活性由单独且不同的酶产生相一致。
