| Summary: | 碩士 === 國防醫學院 === 解剖學研究所 === 83 === Trimeresurus mucrosquamatus, a common venomous snake in
Taiwan, belongs to the family Viperidae. In previous study
we have obtained a partial cDNA clone by immunoscreening from
venom gland cDNA library of T. mucrosquamatus. Partial cDNA
sequence analysis indicate a strong homology with that of
snake venom protein batroxobin. Batroxobin is a thrombin-like
enzyme isolated from Bothrops atrox which are also
member of the family Viperidae. Batroxobin has a
defibrinogenerating effect and is clinically used for the
treatment of thrombotic diseases. In this study, a full-length
cDNA isolated from T. mucrosquamatus and designated as
trimubin. The cDNA sequence and the structure and functional
relationships of trimubin cDNA is characterized. The
5''-rapid amplification of cDNA end (RACE) are used in
the isolation and construction of the full-length cDNA.
Both RACE amplified cDNA and cloned partial cDNA detects a
message with a similar size of 1.5 kb. Northern blot
analysis by this result suggests that the RACE amplifi ed cDNA
and cloned partial cDNA is in the same gene but on the
opposite end. The full-length trimubin cDNA consists of
1576 bp with a 5''-noncoding region of 188 bp and a
3''-noncoding segment of 614 bp. Based on the sequence
homology comparison and Kozak sequence analysis, the protein
translation begins at 189 base and stops at 962 base. The
encoding region in between is 771 bases and could code for
257 amino acids with a calculated molecular weight of 28.1
kDa. A typical poly (A) signal, AATAAA is located 15
bases in the upstream of the poly (A) tail. Amino acid
sequence comparison shows strong homology with venombin A,
ancrod and batroxobin. trimubin is a serine proteinase.
|
|---|
