Читать книгу Handbook of Intelligent Computing and Optimization for Sustainable Development - Группа авторов - Страница 57

Deoxyribozyme logic gate works as AND gate if it is modified by including two stemloop modules. This region regulates the activity of the enzyme by controlling the binding of substrate. The substrate cannot bind to deoxyribozyme if any of the stem-loops is in closed form. As a result, the enzyme is inactivated as no output can be generated. The mechanism is shown in Figure 2.16. If two specific single stranded input DNA sequences, i.e., ix and iy, are added, then these oligonucleotides hybridize to the two loop regions and break the stem-loop structures. Then, the substrate can anneal to the substrate binding regions which causes the substrate cleavage. Hence, the output DNA signal is produced. Thus, the xANDy logic gate is activated only when both the inputs, i.e., ix and iy are present. The addition of any one of the two inputs cannot open both substrate binding regions. The truth table for AND gate is presented is Table 2.1.

Figure 2.15 Mechanism of NOT gate.

Table 2.5 Truth table for NOT gate.

Input (iz)	Output
0	1
1	0

Figure 2.16 Mechanism of AND gate.