Premium
Comparative analysis of two biliproteins, BP1 and BP2, from haemolymph of cabbage white butterfly, Pieris rapae
Author(s) -
Choi Chi Won,
Nam KyungPil,
Seo Dong Hwan,
Choi Jong Woon,
Lee Chang Seok,
Kim Hak Ryul,
Yun ChiYoung
Publication year - 2006
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.20106
Subject(s) - hemolymph , biology , midgut , biochemistry , integument , amino acid , insect , gel electrophoresis , pieris rapae , microbiology and biotechnology , larva , botany
Two blue‐pigment binding proteins, BP1 and BP2, are present in larval and pupal haemolymph of cabbage white butterfly, Pieris rapae , and fluctuate in expression during development. Both BP1 and BP2 are found in pupal haemolymph in varying proportions as well as in adult haemolymph, while only small amounts of BP2 are found in larval haemolymph. BPs are separated by 75% ammonium sulfate, and then purified effectively by ion exchange column chromatography and preparative gel electrophoresis. It was shown that BP1 and BP2 have molecular masses of 20,244 and 19,878 Da, and isoelectric points of 7.0 and 6.8, respectively. Considering their amino acid compositions and N‐terminal amino acid sequences, the two proteins are almost identical except the first N‐terminal amino acid. The first amino acid of BP1 is asparagine, whereas the initial residue of BP2 is aspartic acid. Anti‐BP1 cross‐reacts with BP2, indicating that they have immunological homogeneity. Western blotting analyses revealed that only BP1 was present in the larval tissues such as fat body, integument, muscle, and hindgut. However, BP1 was not found in midgut, Malphigian tubules, and silk gland. BP1 was also present in the protein bodies, and both cuticle and hemocoel sides of larval epidermis cells by the transmission electron microscopic observation. The information in this report will facilitate studies on the molecular biology and biological significance of insect BPs. Arch. Insect Biochem. Physiol. 61:220–230, 2006. © 2006 Wiley‐Liss, Inc.