WELKER N E, CAMPBELL L L
J Bacteriol. 1963 Dec;86(6):1202-10. doi: 10.1128/jb.86.6.1202-1210.1963.
Welker, N. E. (Western Reserve University, Cleveland, Ohio and University of Illinois, Urbana), and L. Leon Campbell. De novo synthesis of alpha-amylase by Bacillus stearothermophilus. J. Bacteriol. 86:1202-1210. 1963.-The pH optimum for the synthesis of alpha-amylase by washed-cell suspensions was 6.7. alpha-Amylase synthesis began soon after the addition of the inducer (maltose, methyl-beta-d-maltoside, or phenyl-alpha-d-glucoside, at 10(-3)m), proceeded at a linear rate for 60 min, and then leveled off. Cell suspensions without inducer produced small amounts of alpha-amylase. The addition of glucose (2 x 10(-3)m), sucrose (10(-3)m), or glycerol (4 x 10(-3)m) to washed-cell suspensions failed to stimulate the production of alpha-amylase. Nitrogen starvation of washed cells for 60 min with fructose as a carbon source or by induction with pure maltose showed that the ability to produce alpha-amylase was lost. Examination of the amino acid pool at this time showed a general depletion of amino acids and the complete disappearance of tyrosine, phenyl-alanine, proline, and valine. Replenishment of the amino acid pool with casein hydrolysate (0.5%) restored the ability of the cells to produce alpha-amylase. Chloramphenicol and 8-azaguanine were shown to inhibit alpha-amylase synthesis. Inhibition was observed immediately upon the addition of chloramphenicol to cell suspensions preinduced for varying periods of time. Actinomycin D and mitomycin C also inhibited alpha-amylase synthesis when added to induced washed-cell suspensions. The amino acid analogues, norvaline, norleucine, and ethionine, inhibited alpha-amylase formation by 72, 53, and 38%, respectively. p-Fluorophenylalanine inhibited the synthesis of active alpha-amylase by 92% and the incorporation of proline-C(14) into alpha-amylase and cellular proteins by 95 and 74%, respectively.
韦尔克，N. E.（俄亥俄州克利夫兰市西部保留地大学和伊利诺伊大学厄巴纳分校），以及L. 利昂·坎贝尔。嗜热脂肪芽孢杆菌α-淀粉酶的从头合成。《细菌学杂志》86:1202 - 1210。1963年。 - 洗涤细胞悬液合成α-淀粉酶的最适pH值为6.7。添加诱导剂（麦芽糖、甲基-β-D-麦芽糖苷或苯基-α-D-葡萄糖苷，浓度为10⁻³m）后不久，α-淀粉酶合成开始，以线性速率进行60分钟，然后趋于平稳。无诱导剂的细胞悬液产生少量α-淀粉酶。向洗涤细胞悬液中添加葡萄糖（2×10⁻³m）、蔗糖（10⁻³m）或甘油（4×10⁻³m）未能刺激α-淀粉酶的产生。以果糖为碳源或用纯麦芽糖诱导洗涤细胞60分钟使其氮饥饿，结果表明产生α-淀粉酶的能力丧失。此时对氨基酸库的检测显示氨基酸普遍耗竭，酪氨酸、苯丙氨酸、脯氨酸和缬氨酸完全消失。用酪蛋白水解物（0.5%）补充氨基酸库可恢复细胞产生α-淀粉酶的能力。氯霉素和8-氮杂鸟嘌呤被证明可抑制α-淀粉酶的合成。在将氯霉素添加到预先诱导不同时间的细胞悬液后立即观察到抑制作用。放线菌素D和丝裂霉素C添加到诱导的洗涤细胞悬液中时也抑制α-淀粉酶的合成。氨基酸类似物正缬氨酸、正亮氨酸和乙硫氨酸分别抑制α-淀粉酶形成72%、53%和38%。对氟苯丙氨酸分别抑制活性α-淀粉酶的合成92%，以及脯氨酸-C¹⁴掺入α-淀粉酶和细胞蛋白的95%和74%。
