Microbial production of sensory-active miraculin
Microbial production of sensory-active miraculin
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DOI：
10.1016/j.bbrc.2007.06.064
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发表时间：
2007-08-24
影响因子：
3.1
通讯作者：
Abe, Keiko
中科院分区：
文献类型：
--
作者：
Ito, Keisuke;Asakura, Tomiko;Abe, Keiko
奇迹果蛋白（MCL），一种热带水果蛋白，是独特的，因为它具有口味修饰活性，将酸味转换为甜味，虽然在中性pH值的口味平坦。为了获得足够量的MCL，以研究在分子水平上参与这一感官事件的机制，我们通过引入MCL基因转化了黑曲霉。转化体表达并分泌产生2 mg/L的MCL的感觉活性形式。重组MCL类似于天然MCL的二级结构和口味修饰活性，在酸性pH值下产生甜味。由于所观察到的pH-甜味关系似乎反映了咪唑滴定曲线，表明组氨酸残基可能参与口味修饰活性。H30 A和H30，60 A突变体是利用A.水稻介导的表达系统发现两种突变体都失去了味觉修饰活性。结果表明，组氨酸-30残基对MCL的矫味活性有重要影响。(C)2007年由Elsevier Inc.出版
Miraculin (MCL), a tropical fruit protein, is unique in that it has taste-modifying activity to convert sourness to sweetness, though flat in taste at neutral pH. To obtain a sufficient amount of MCL to examine the mechanism involved in this sensory event at the molecular level, we transformed Aspergillus oryzae by introducing the MCL gene. Transformants were expressed and secreted a sensory-active form of MCL yielding 2 mg/L. Recombinant MCL resembled native MCL in the secondary structure and the taste-modifying activity to generate sweetness at acidic pH. Since the observed pH-sweetness relation seemed to reflect the imidazole titration curve, suggesting that histidine residues might be involved in the taste-modifying activity. H30A and H30,60A mutants were generated using the A. oryzae-mediated expression system. Both mutants found to have lost the taste-modifying activity. The result suggests that the histidine-30 residue is important for the taste-modifying activity of MCL. (C) 2007 Published by Elsevier Inc.