MSU-DOE Plant Research Laboratory, Michigan State University, 48824, East Lansing, MI, USA.
Planta. 1979 Jan;145(3):293-303. doi: 10.1007/BF00454455.
A simple and sensitive chemical assay was developed for 1-aminocyclopropane-1-carboxylic acid (ACC), a precursor of ethylene. The assay is based on the liberation of ethylene from ACC at pH 11.5 in the presence of pyridoxal phosphate, MnCl2 and H2O2. This assay was used to detect ACC in extracts of tomato fruits (Lycopersicon esculentum Mill.) and to measure the activity of a soluble enzyme from tomato fruit that converted S-adenosylmethionine (SAM) to ACC. The enzyme had a Km of 13 μM for SAM, and conversion of SAM to ACC was competitively and reversibly inhibited by aminoethoxyvinylglycine (AVG), an analog of rhizobitoxine. The Ki value for AVG was 0.2 μM. The level of the ACC-forming enzyme activity was positively correlated with the content of ACC and the rate of ethylene formation in wild-type tomatoes of different developmental stages. Mature fruits of the rin (non-ripening) mutant of tomato, which only produce low levels of ethylene, contained much lower levels of ACC and of the ACC-forming enzyme activity than wild-type tomato fruits of comparable age.
开发了一种简单灵敏的 1-氨基环丙烷-1-羧酸（ACC）化学分析方法，ACC 是乙烯的前体。该分析方法基于在 pH 值为 11.5 的条件下，ACC 在吡哆醛磷酸盐、MnCl2 和 H2O2 的存在下释放乙烯。该分析方法用于检测番茄果实（Lycopersicon esculentum Mill.）提取物中的 ACC，并测量番茄果实中一种可将 S-腺苷甲硫氨酸（SAM）转化为 ACC 的可溶性酶的活性。该酶对 SAM 的 Km 为 13 μM，SAM 转化为 ACC 受到氨基乙氧基乙烯基甘氨酸（AVG）的竞争性和可逆抑制，AVG 是根瘤菌素的类似物。AVG 的 Ki 值为 0.2 μM。形成 ACC 的酶活性的水平与不同发育阶段野生型番茄中 ACC 的含量和乙烯形成的速率呈正相关。番茄 rin（非成熟）突变体的成熟果实仅产生低水平的乙烯，其 ACC 和形成 ACC 的酶活性水平远低于可比年龄的野生型番茄果实。
