MOLECULAR-CLONING AND SEQUENCING OF 2 CDNAS ENCODING CATHEPSIN L-RELATED CYSTEINE PROTEINASES IN THE NERVOUS-SYSTEM AND IN THE STOMACH OF THE NORWAY LOBSTER (NEPHROPS-NORVEGICUS)
C. Leboulay et al., MOLECULAR-CLONING AND SEQUENCING OF 2 CDNAS ENCODING CATHEPSIN L-RELATED CYSTEINE PROTEINASES IN THE NERVOUS-SYSTEM AND IN THE STOMACH OF THE NORWAY LOBSTER (NEPHROPS-NORVEGICUS), Comparative biochemistry and physiology. B. Comparative biochemistry, 111(3), 1995, pp. 353-359
Two cathepsin L-related cysteine proteinase molecular clones were isol
ated from cDNA libraries of mRNA from the eyestalk nervous system and
the stomach of Nephrops norvegicus and sequenced. The cDNA from nervou
s system was first obtained by screening an eyestalk cDNA library with
an oligonucleotide whose sequence derived from the amino acid sequenc
e of a peptide isolated previously and subsequently with the 5' end of
the longest cDNA probe thus obtained. Several clones were isolated an
d analysed: one of these clones contains the complete cDNA (NCP1: AC =
X80989). It encodes a preproenzyme of 324 amino acid residues, and a
putative mature enzyme of 217 residues. Only one variant (with one ami
no acid change) was identified. The screening of the stomach cDNA libr
ary was carried out with a cDNA probe corresponding to the 5' terminal
region of the nervous system cysteine proteinase cDNA previously obta
ined, A near full-length cDNA (NCP2: AC = X80990) was isolated. The se
quence for mature stomach cathepsin L-related cysteine proteinase is 2
15 residues long. Nervous system cathepsin L-like NCP1 is very similar
to the American lobster cysteine proteinase LCP1 (81% identity) and t
he stomach cathepsin L-related NCP2 is very similar to cysteine protea
se LCP3 (82% identity). Moreover, comparison of the two Nephrops norve
gicus cathepsin L-related cysteine proteinases revealed only 68% ident
ity.