Table 2. Characterizations of charge and H-bond properties.

Enzyme	SxxK Charge	ExxLN Charge	Ω-loop Charge	Total Charge	Total HB Energy	Number of HB	Avg. HB Energy
G	1	−2	−2	−3	−1631.3	559	−2.9
TEM-1	1	−2	−4	−5	−1609.6	513	−3.1
NMC-A	1	−2	−3	1	−1588.3	520	−3.1
SME-1	1	−2	−1	7	−1728.4	550	−3.1
PSE-4	1	−2	−2	−4	−1548.0	529	−2.9
TEM-52	1	−2	−4	1	−1590.9	557	−2.9
L2	1	−2	−1	2	−1534.6	528	−2.9
SHV-2	1	−2	−3	1	−1633.2	539	−3.0
SHV-1	1	−2	−3	1	−1570.7	532	−3.0
MFO	1	−2	−2	−6	−1503.0	507	−3.0
PC1	1	−2	2	15	−1559.3	495	−3.2
BS3	1	−2	−4	−5	−1669.1	522	−3.2
Average	1	−2	−2.3	0.4	−1597.2	529.3	−3.0
CV 1	0.0%	0.0%	76.1%	1430.7%	3.9%	3.7%	3.8%

¹Coefficient of variation = standard deviation/mean * 100.