A family of textilinin genes, two of which encode proteins with antihaemorrhagic properties.
Two peptides, textilinins 1 and 2, isolated from the venom of the Australian common brown snake, Pseudonaja textilis textilis, are effective in preventing blood loss. To further investigate the potential of textilinins as antihaemorrhagic agents, we cloned cDNAs encoding these proteins. The isolated full-length cDNA (430 bp in size) was shown to code for a 59 amino acid protein, corresponding in size to the native peptide, plus an additional 24 amino acid propeptide. Six such cDNAs were identified, differing in nucleotide sequence in the coding region but with an identical propeptide. All six sequences predicted peptides containing six conserved cysteines common to Kunitz-type serine protease inhibitors. When expressed as glutathione S-transferase (GST) fusion proteins and released by cleavage with thrombin, only those peptides corresponding to textilinin 1 and 2 were active in inhibiting plasmin with Ki values similar to those of their native counterparts and in binding to plasmin less tightly than aprotinin by two orders of magnitude. Similarly, in the mouse tail vein blood loss model only recombinant textilinin 1 and 2 were effective in reducing blood loss. These recombinant textilinins have potential as therapeutic agents for reducing blood loss in humans, obviating the need for reliance on aprotinin, a bovine product with possible risk of transmissible disease, and compromising the fibrinolytic system in a less irreversible manner.
Filippovich
Igor
I
The Queensland Cancer Fund Research Unit, The Queensland Institute of Medical Research, Royal Brisbane Hospital, Herston, Australia.
Sorokina
Natasha
N
Masci
Paul P
PP
de Jersey
John
J
Whitaker
Alan N
AN
Winzor
Donald J
DJ
Gaffney
Patrick J
PJ
Lavin
Martin F
MF
D000595:Amino Acid Sequence; D000818:Animals; D019677:Artificial Gene Fusion; D016063:Blood Loss, Surgical / Q000517:prevention & control*; D003001:Cloning, Molecular; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000235:genetics*; D004546:Elapid Venoms / Q000235:genetics* / Q000494:pharmacology; D006490:Hemostatics / Q000494:pharmacology; D051379:Mice; D023421:Models, Animal; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D012910:Snake Venoms; D013623:Tail / Q000098:blood supply
D018076:DNA, Complementary; D004546:Elapid Venoms; D006490:Hemostatics; D011994:Recombinant Proteins; D012910:Snake Venoms; C413544:textilinin