Electronic Journal of Biotechnology ISSN: 0717-3458
  © 2004 by Universidad Católica de Valparaíso -- Chile
Vol. 7 No. 2, Issue of August 15, 2004 
 

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

 

Supported by UNESCO / MIRCEN network