Characterization of bullet tuna myoglobin with reference to the thermostability-structure relationship.
Myoglobin (Mb) was isolated from bullet tuna (Auxis rochei) skeletal muscle and characterized from the viewpoint of the thermostability-structure relationship. Differential scanning calorimetry (DSC) measurement showed that the thermostability of bullet tuna Mb was the lowest among all the scombridae fish Mbs so far examined. The highest value (72.8 degrees C) of melting temperature (Tm) was obtained at pH 6.52. alpha-Helical content at 10 degrees C was 34.5%, clearly lower than that of horse Mb (55.3%). The amino acid sequence was then deduced by cloning cDNA which encodes bullet tuna Mb. Bullet tuna Mb consisted of 147 amino acids, and the sequence identity was very close to that of skipjack (Katsuwonus pelamis) Mb (91.8%). A few amino acid substitutions, which could be involved in stability difference of Mb, were recognized. By mass spectrometry of lysyl endoproteinase digest of Mb, the N-terminus was found to be acetylated like that of other fish Mbs.
Ueki
Nobuhiko
N
Laboratory of Aquatic Molecular Biology and Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
Chow
Chau-Jen
CJ
Ochiai
Yoshihiro
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004355:Drug Stability; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009211:Myoglobin / Q000737:chemistry* / Q000235:genetics; D017433:Protein Structure, Secondary; D013329:Structure-Activity Relationship; D014413:Tuna
D018076:DNA, Complementary; D009211:Myoglobin