Differential scanning calorimetry and circular dichroism spectrometry of walleye pollack myosin and light meromyosin.
The thermodynamic properties of myosin and its C-terminal fragment, light meromyosin (LMM), from walleye pollack, a typical cold-water fish efficiently utilized on an industrial scale, were analyzed by using differential scanning calorimetry (DSC) and circular dichroism (CD) spectrometry. Recombinant walleye pollack LMM expressed in Escherichia coli was also subjected to DSC and CD measurements for reference. The two proteins prepared from frozen surimi showed three endothermic peaks, the transition temperatures (T(m)) of which were quite similar, although overall DSC patterns differed considerably from one another. Their alpha-helical contents determined by CD were low compared to values reported before for other species. On the other hand, recombinant LMM gave four endothermic peaks at 27.4, 30.8, 36.5, and 43.4 degrees C in DSC and showed an alpha-helical content of approximately 80%. The peak at 27.4 degrees C could not be observed in walleye pollack LMM prepared from frozen surimi and thus was possibly attributed to its C terminus, because this extreme C-terminal region is supposedly truncated during preparation of LMM by tryptic digestion.
Togashi
Marie
M
Laboratory of Aquatic Molecular Biology and Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
Kakinuma
Makoto
M
Nakaya
Misako
M
Ooi
Tatsuo
T
Watabe
Shugo
S
D000595:Amino Acid Sequence; D000818:Animals; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D003080:Cold Temperature; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D005399:Fishes; D008969:Molecular Sequence Data; D015879:Myosin Subfragments / Q000737:chemistry* / Q000235:genetics; D009218:Myosins / Q000737:chemistry*; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D013816:Thermodynamics; D014357:Trypsin / Q000378:metabolism
D015879:Myosin Subfragments; D011994:Recombinant Proteins; D014357:Trypsin; D009218:Myosins