Russell D H, Potyraj J J
Biochem J. 1972 Aug;128(5):1109-15. doi: 10.1042/bj1281109.
We reported that spermidine and spermine pools in the uterus both doubled within 24h after oestradiol administration to castrated rats (Russell & Taylor, 1971). Now we have studied the enzymic synthesis of spermine (by spermidine-dependent S-adenosyl-l-methionine decarboxylase) and find that the activity of the enzyme(s) involved is elevated soon after hormone administration. Enzyme activity is increased within 4h and is five times that of controls within 24h. Cycloheximide or actinomycin D administered at the time of oestradiol injection completely blocked the increase in enzyme activity. The enzyme involved in spermine synthesis, S-adenosyl-l-methionine decarboxylase, with S-adenosyl-l-methionine and spermidine as required substrates, was partially purified on Sephadex and DEAE-cellulose columns. The decarboxylation of S-adenosyl-l-methionine could not be separated from the transfer of a propylamine moiety from the decarboxylated S-adenosyl-l-methionine to spermidine to form spermine. We were unable also to separate this system from the enzyme that formed spermidine when S-adenosyl-l-methionine and putrescine are used as substrates. Spermidine-stimulated S-adenosyl-l-methionine decarboxylase has an apparent half-life of 60min, identical with the half-life reported for putrescine-stimulated S-adenosyl-l-methionine decarboxylase. These results strongly suggest that the same enzyme(s) operate in the synthesis of both spermidine and spermine.
我们曾报道，给去势大鼠注射雌二醇后24小时内，子宫中的亚精胺和精胺池均增加了一倍（拉塞尔和泰勒，1971年）。现在我们研究了精胺的酶促合成（通过依赖亚精胺的S-腺苷-L-甲硫氨酸脱羧酶），发现相关酶的活性在激素给药后很快升高。酶活性在4小时内增加，24小时内是对照组的五倍。在注射雌二醇时给予环己酰亚胺或放线菌素D可完全阻断酶活性的增加。参与精胺合成的酶，即S-腺苷-L-甲硫氨酸脱羧酶，以S-腺苷-L-甲硫氨酸和亚精胺作为所需底物，在葡聚糖凝胶和二乙氨基乙基纤维素柱上进行了部分纯化。S-腺苷-L-甲硫氨酸的脱羧反应与丙胺部分从脱羧的S-腺苷-L-甲硫氨酸转移至亚精胺以形成精胺的过程无法分离。当以S-腺苷-L-甲硫氨酸和腐胺作为底物时，我们也无法将该系统与形成亚精胺的酶分离。亚精胺刺激的S-腺苷-L-甲硫氨酸脱羧酶的表观半衰期为60分钟，与报道的腐胺刺激的S-腺苷-L-甲硫氨酸脱羧酶的半衰期相同。这些结果强烈表明，同一酶参与了亚精胺和精胺的合成。
