Lewis R S, Jung G, Köhnlein W
Biochim Biophys Acta. 1980 Jun 27;608(1):138-46. doi: 10.1016/0005-2787(80)90141-0.
Sulfhydryl compounds specifically activate and inactive neocarzinostatin as measured by the in vitro strand scission of T2 DNA. This effect, and evidence for strained disulfides in the molecule, leads us to propose a model of activation and inactivation. We suggest that neocarzinostatin reacts with sulfhydryl reagents to produce a short-lived active form which may react with DNA or proceed irreversibly via a conformational change to an inactive form (preneocarzinostatin). Three parameters of neocarzinostatin activity (inactivation rate, single strand break plateau position, and initial single strand break rate), have been measured for various sulfhydryl concentrations, and the observed results agree well with values expected from a simplified mathematical treatment of the model, thus supporting the assumptions made.
巯基化合物通过T2 DNA的体外链断裂测定法，能特异性地激活或使新制癌菌素失活。这种效应以及分子中存在张力二硫键的证据，促使我们提出了一个激活和失活模型。我们认为新制癌菌素与巯基试剂反应生成一种寿命短暂的活性形式，该活性形式可能与DNA反应，或者通过构象变化不可逆地转变为无活性形式（前新制癌菌素）。针对不同的巯基浓度，已测定了新制癌菌素活性的三个参数（失活速率、单链断裂平台位置和初始单链断裂速率），观察结果与该模型简化数学处理所预期的值非常吻合，从而支持了所做的假设。
