The possible involvement of specific regions/loops of cardiotoxin from Naja sputatrix venom in mediating its cytolytic activity is evaluated using a new cytolytic assay. In this assay, the amount of chloramphenicol acetyltransferase (CAT) that is released upon lysis of the cellular membranes by the cytotoxin has been measured as an index of cytolysis. This newly developed CAT system is more sensitive than the traditional haemolysis method utilizing red blood cells or the lactate dehydrogenase assay for cytolysis. Series of chimaeric toxin molecules have been constructed by swapping the loops between highly hydrophilic neurotoxin and highly hydrophobic cardiotoxin molecules from Naja sputatrix, which are known to exhibit structural similarity (three-finger conformation) but to have different functional properties. Comparison of the cytolytic activities of the recombinant chimaeric toxins demonstrated the possible involvement of all three loops of cardiotoxin in its cytolytic potency. However, the first two loops of the protein appear to make the major contribution to its lytic activity. cDNAs encoding cardiotoxin and the chimaeric toxins, when expressed in transfected cultured Chinese hamster ovary cells, resulted in cell lysis, indicating that these cDNAs can be developed as useful cytolytic agents.
Skip Nav Destination
Article navigation
August 2002
- PDF Icon PDF LinkFront Matter
Research Article|
August 15 2002
Cytotoxic potency of cardiotoxin from Naja sputatrix: development of a new cytolytic assay
Donghui MA;
Donghui MA
Department of Biochemistry, Faculty of Medicine, National University of Singapore, 10 Medical Drive, Singapore 119260
Search for other works by this author on:
Arunmozhiarasi ARMUGAM;
Arunmozhiarasi ARMUGAM
Department of Biochemistry, Faculty of Medicine, National University of Singapore, 10 Medical Drive, Singapore 119260
Search for other works by this author on:
Kandiah JEYASEELAN
Kandiah JEYASEELAN
1
Department of Biochemistry, Faculty of Medicine, National University of Singapore, 10 Medical Drive, Singapore 119260
1To whom correspondence should be addressed (e-mail bchjeya@nus.edu.sg).
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
March 19 2002
Revision Received:
May 21 2002
Accepted:
May 24 2002
Online ISSN: 1470-8728
Print ISSN: 0264-6021
The Biochemical Society, London ©2002
2002
Biochem J (2002) 366 (1): 35–43.
Article history
Received:
March 19 2002
Revision Received:
May 21 2002
Accepted:
May 24 2002
Citation
Donghui MA, Arunmozhiarasi ARMUGAM, Kandiah JEYASEELAN; Cytotoxic potency of cardiotoxin from Naja sputatrix: development of a new cytolytic assay. Biochem J 15 August 2002; 366 (1): 35–43. doi: https://doi.org/10.1042/bj20020437
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.