B. Klein et al., MOLECULAR-CLONING AND SEQUENCING OF TRYPSIN CDNAS FROM PENAEUS-VANNAMEI (CRUSTACEA, DECAPODA) - USE IN ASSESSING GENE-EXPRESSION DURING THEMOLT CYCLE, International journal of biochemistry & cell biology, 28(5), 1996, pp. 551-563
Trypsin is the most abundant protease in Crustacea. This enzyme was pu
rified from the digestive gland of Penaeus vannamei, revealing three m
ajor isoforms (molecular weights 31-32 kDa) and several minor componen
ts, Five cDNAs encoding five isoforms of trypsin were detected by two
successive screenings of an amplified cDNA library from the digestive
gland of P. vannamei. The longest isolated and sequenced cDNA encoded
a preproenzyme of 255 amino acids containing a putative precursor pept
ide of 14 residues and a highly hydrophobic signal sequence of 14 amin
o acids, Amino acid sequence alignments revealed a high degree of iden
tity between the trypsin from P. vannamei and that from crayfish (74%)
and an equal level of sequence similarity to that from mammals and in
sects (approximate to 40). Dot blot hybridization and subsequent analy
sis of the variation in trypsin-specific activities revealed that mRNA
expression is at a maximum during early premoult (D-1), declining sha
rply in late premoult (D-2-D-3). The specific activity of trypsin also
followed this pattern, suggesting the regulation of trypsin biosynthe
sis is, at least in part, transcriptional. The characterization of try
psin cDNA from P. vannamei provides the first description of a putativ
e zymogen sequence in a crustacean species, enabling us to elucidate t
he regulatory mechanism of trypsin synthesis in these important marine
organisms. Copyright (C) 1996 Elsevier Science Ltd.