Houghton J D, Turner L, Brown S B
Department of Biochemistry, University of Leeds, U.K.
Biochem J. 1988 Sep 15;254(3):907-10. doi: 10.1042/bj2540907.
Pigment synthesis in four strains of the unicellular red alga Cyanidium caldarium with different pigment-synthesizing patterns was inhibited in the presence of gabaculine (3-amino-2,3-dihydrobenzoic acid). Parallel inhibition of light-induced chlorophyll and phycocyanin synthesis was observed in strain III-D-2, which only synthesizes pigments in the light. Similar parallel inhibition was observed in the dark in mutant CPD, which is able to synthesize chlorophyll and phycocyanin in the absence of light. Inhibition of pigment synthesis in all strains was overcome by addition of 5-aminolaevulinic acid. Inhibition of phycocyanin synthesis in mutant GGB (unable to synthesize chlorophyll) and inhibition of chlorophyll synthesis in mutant III-C (unable to synthesize phycocyanin) were also observed. Gabaculine also inhibited the heterotrophic growth of C. caldarium in the dark. However, inhibition was overcome after an extended lag period, following which cell growth proceeded at a similar rate to that of control cells not exposed to gabaculine. Heterotrophic growth in cells pre-exposed to gabaculine was not inhibited by subsequent exposure. Possible mechanisms for this adaptation are discussed.
在加巴喷丁（3-氨基-2,3-二氢苯甲酸）存在的情况下，四种具有不同色素合成模式的单细胞红藻蓝氏红球藻菌株中的色素合成受到抑制。在仅在光照下合成色素的III-D-2菌株中，观察到光诱导的叶绿素和藻蓝蛋白合成受到平行抑制。在能够在无光条件下合成叶绿素和藻蓝蛋白的突变体CPD中，在黑暗中也观察到类似的平行抑制。通过添加5-氨基乙酰丙酸克服了所有菌株中色素合成的抑制。在突变体GGB（无法合成叶绿素）中观察到藻蓝蛋白合成的抑制，在突变体III-C（无法合成藻蓝蛋白）中观察到叶绿素合成的抑制。加巴喷丁还抑制了蓝氏红球藻在黑暗中的异养生长。然而，在延长的延迟期后抑制被克服，此后细胞生长以与未暴露于加巴喷丁的对照细胞相似的速率进行。预先暴露于加巴喷丁的细胞中的异养生长不受随后暴露的抑制。讨论了这种适应的可能机制。
