Table 3 - Protein engineering of d-endotoxins of Bacillus thuringiensis

Table 3. Mutants with enhanced or novel toxicity.

S.no.	Toxin	Fold increase in toxicity than wild type toxin -Insect tested	Effect	Reference
1.	Cry1Ac H168R	+2 M. Sexta	High irreversible binding	Wu and Aronson, 1992
2.	Cry4B domain I	+3 Mosquito	Removing site of proteolytic instability	Angsuthanasombat et al. 1993
3.	CryA Loop3 451MOGSRG 486	+2.4 Tenebrio molitor	Improvement in irreversible binding	Lee et al. 1995
4.	Cry1Ac N327A N372G	+8, Lymantrea dispar	Increased initial binding	Rajamohan et al. 1996a
5.	N372A A282G L283S	+36, Lymantrea dispar	Higher binding affinity and binding site concentration	Rajamohan et al. 1996b
6.	Cry1E and Cry1C Domain III exchange	Spodoptera exigiua	IE-IE-IC hybrid showed toxicity with different receptor binding	Bosch et al. 1994
7.	Cry1Ab and Cry1C hybrid	+2.5 that of Cry1Ab and +19.5 that of Cry1C, Plutella xylostella	High affinity binding due to domain III exchange	Ballester et al. 1999
8.	Cry3A loop1	+11.4 Tenebrio molisor	--	Schnepf et al. 1998
9.	Mutation in a helix7 of Cry1Ac with that of Diphtheria toxin hydrophobic domain	+8 fold on Heliothis armigera	Large pore and increased conductance	Chandra et al. 1999
10.	Cry1Ba and Cry1Ia hybrid	+42, Tenebrio molisor	Enhanced toxicity due optimum combination of Domains	Samir et al. 2001
11.	Transnational fusion of Cry1Ab-Cry1C	Heliothis virescence and spodoptera litura	Enlarged toxicity	Honee et al. 1990
12.	Cry1Ac F134L	+3 Manduca Sexta and Heliothis virescence	-	Manoj Kumar and Aronson, 1999
13.	Cry4Ba loop 3 domain II amino acid substitution	+700, Culex quinquesfaciatus +285, Culex pipiens	-	Abdullah et al. 2003