Takáts A, Binh V H, Offenmüller K, Bodó K, Bertók L, Köteles G J
Frederic Joliot-Curie, National Research Institute for Radiology and Radiohygiene, Hungary.
J Radiat Res. 1993 Jun;34(2):141-7. doi: 10.1269/jrr.34.141.
A dose dependent but not parallel decreases were observed both in SH content and catalytic activity of "free" catalytic subunit after irradiation (0-3200 Gy), while SH groups of membrane-associated adenylate cyclase were insensitive (under 3200 Gy). An initial "radioactivation" of membrane-associated enzyme was found under 800 Gy, then an inhibition above 1600 Gy. The SH alkylating agent, N-ethylmaleimide resulted in a complete inactivation, both of membrane associated form of adenylate cyclase and "free" catalytic subunit with similar inactivation profiles. These data indicate that in the radiosensitivity or "radioprotection" of adenylate cyclase, its membrane association/integration might play a more important role than the SH groups themselves.
照射（0 - 3200 Gy）后，“游离”催化亚基的SH含量和催化活性均呈现剂量依赖性降低，但并非平行降低，而膜相关腺苷酸环化酶的SH基团不敏感（3200 Gy以下）。在800 Gy以下发现膜相关酶有初始“放射激活”现象，1600 Gy以上则出现抑制。SH烷基化剂N - 乙基马来酰亚胺导致膜相关形式的腺苷酸环化酶和“游离”催化亚基完全失活，失活曲线相似。这些数据表明，在腺苷酸环化酶的放射敏感性或“放射防护”方面，其膜结合/整合可能比SH基团本身发挥更重要的作用。
