Sarafotoxins:Cloning of mRNAs Encoding Sarafotoxin Precursors

Abstract

Whe applied to animal toxins, molecular biology technologies offer several interests, including the possibility to elucidate the structure of toxin precursors(Ducancel et al., 1991). In General, purified messenger RNAs (mRNAs) are converted into stable complementary copies of DNA (cDNAs) which are then cloned info recombinant vectors and used to transform bacteria. Two screening strategies can be considered to identify clones containing the precursor nucleic information. One of them consist is performing in situ hybridizations (Sambrook et al., 1989), using labeled nucleic acid probes that are complementary to a portion of the precursor sequence. The other strategy consist in using cloning/expression vectors such as λgt11 or pBluescript, and in screening with precursor-specific antibodies (Mierendorf et al., 1987). The nucleic informations contained in the screened clones are then elucidated by DNA sequencing (Sanger et al., 1977)