Spathas D H, Pateman J A, Clutterbuck A J
J Gen Microbiol. 1982 Mar;128(3):557-63. doi: 10.1099/00221287-128-3-557.
The uptake of putrescine, spermidine and spermine was studied in Aspergillus nidulans using 14C-labelled polyamines. Active transport systems, inhibited by azide and regulated by nitrogen availability, exist at least for putrescine and spermidine. Putrescine is taken up two to three times more rapidly than spermidine, reflecting a lower Km for the former substrate. The two uptake systems appear to be independent, spermidine uptake being inhibited by both putrescine and spermine, while putrescine uptake is not inhibited by the other two polyamines. The relationships of these transport systems to the tenfold or greater difference between spermidine and putrescine concentrations required to support growth of the putrescine auxotroph are discussed.
利用14C标记的多胺研究了构巢曲霉对腐胺、亚精胺和精胺的摄取。至少对于腐胺和亚精胺存在受叠氮化物抑制且受氮供应调节的主动运输系统。腐胺的摄取速度比亚精胺快两到三倍，这反映出前者底物的米氏常数较低。这两种摄取系统似乎是独立的，亚精胺的摄取受到腐胺和精胺两者的抑制，而腐胺的摄取不受其他两种多胺的抑制。讨论了这些运输系统与支持腐胺营养缺陷型生长所需的亚精胺和腐胺浓度之间十倍或更大差异的关系。
