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The primary structure of iodopsin, a chicken red‐sensitive cone pigment
Author(s) -
Kuwata Osamu,
Imamoto Yasushi,
Okano Toshiyuki,
Kokame Koichi,
Kojima Daisuke,
Matsumoto Hiroki,
Morodome Akihiro,
Fukada Yoshitaka,
Shichida Yoshinori,
Yasuda Kunio,
Shimura Yoshiro,
Yoshizawa Tôru
Publication year - 1990
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(90)80465-u
Subject(s) - rhodopsin , chymotrypsin , pigment , complementary dna , transmembrane protein , peptide sequence , transmembrane domain , homology (biology) , amino acid , chemistry , protein primary structure , biochemistry , microbiology and biotechnology , biology , enzyme , trypsin , gene , receptor , retinal , organic chemistry
A purified iodopsin was digested by CNBr or several proteolytic enzymes into fragments, the amino acid sequences of which were determined. A partial sequence of the C‐terminal fragment was utilized for synthesizing an oligonucleotide probe which identified the iodopsin cDNA (1339 bases). The deduced amino acid sequence (362 residues) had 80%, 42% or 43% homology to that of human red‐sensitive cone pigment, cattle or chicken rhodospin, respectively. Although the hydropathy profile implies that iodopsin, like rhodopsin, has 7 transmembrane α‐helical segments, iodopsin may have a hydrophilic pocket near the seventh segment on the basis of the unexpected cleavages in the middle of the segment VII by chymotrypsin under nondenaturing conditions.