三层安全防线 · 双自杀开关 · 防水平转移
唾液链球菌 K12
cspA 5'UTR + RelE
口腔38°C关闭 · 室温<30°C激活
Pasr + RelE
口腔pH>6关闭 · 胃酸pH<5激活
三层安全防线 · 从底盘到基因层层防护 · 确保绝对安全
| 温度 (°C) | 相对表达活性 (%) |
|---|---|
| 15°C | 65% |
| 20°C | 52% |
| 25°C | 38% |
| 30°C | 18% |
| 37°C | 2% |
温度响应特性
口腔 (37°C) → 2% (关闭) · 室温 (25°C) → 38% (激活) · 低温 (15°C) → 65% (强激活)
| pH值 | 相对表达活性 (%) |
|---|---|
| 8.0 | 5% |
| 7.0 | 5% |
| 6.0 | 25% |
| 5.5 | 50% |
| 5.0 | 100% |
| 4.5 | 75% |
| 4.0 | 50% |
| 3.0 | 35% |
pH响应特性
口腔 (pH 7) → 5% (关闭) · 胃酸 (pH 5) → 100% (峰值激活) · 强酸 (pH 3) → 35% (维持)
| 环境 | 温度 | pH | 温度通路 | pH通路 | 结果 |
|---|---|---|---|---|---|
| 口腔内 | 38°C | 7.0 | 关闭 | 关闭 | ✅ 存活 |
| 室温 | 25°C | 7.0 | 激活 | 关闭 | ❌ 死亡 |
| 胃酸 | 38°C | 3.0 | 关闭 | 激活 | ❌ 死亡 |
| 环境水体 | 25°C | 6.0 | 激活 | 低表达 | ❌ 死亡 |
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