Identification and characterization of two chitin-binding proteins from the peritrophic membrane of the silkworm, Bombyx mori L.
The peritrophic membrane (PM) is a semi-permeable lining of the insect midgut, broadly analogous to the mucous lining of vertebrate gut. The PM proteins are important achievements for the function of the PM. In this study, two chitin-binding proteins (BmPM-P43 and BmPM-P41) from the PM of the silkworm, Bombyx mori, were identified and cloned. These proteins showed the molecular mass of 43 and 41 kDa, respectively. The deduced amino acid sequences codes for a protein of 381 amino acid residues and 364 amino acid residues, containing 12 and 14 cysteine residues followed by similar domain, both of them have 5 cysteine residues in similar position in the C-terminal. The confirmation of these proteins was performed by western blot analysis of recombinant BmPM-P43 and BmPM-P41. The chitin-binding activity analysis showed that the BmPM-P43 and BmPM-P41 could bind to chitin strongly. It is concluded that BmPM-P43 and BmPM-P41 contains a polysaccharide deacetylase domain instead of peritrophin domain, indicated that these two proteins may belong to a new chitin-binding protein family.
Key Laboratory of Animal Epidemic Etiology & Immunological Prevention of Ministry of Agriculture, Zhejiang University, Hangzhou, People's Republic of China.
Hua-Jun
HJ
Yang
Fang
F
Zhou
Firdose Ahmad
FA
Malik
Roy
R
Bhaskar
Xing-Hua
XH
Li
Jia-Biao
JB
Hu
Chun-Guang
CG
Sun
Yun-Gen
YG
Miao
D000581:Amidohydrolases / Q000737:chemistry / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D002686:Chitin / Q000378:metabolism*; D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment
D019476:Insect Proteins; D002686:Chitin; D000581:Amidohydrolases; C019866:chitin deacetylase