Identification of Whale Species by Thin-Layer Isoelectric Focusing of Sarcoplasmic Proteins1

• Published in: Journal of AOAC INTERNATIONAL
• Main Authors: Ukishima, Yoshiyuki, Kino, Masahiko, Kubota, Hiroyuki, Wada, Shiro, Okada, Shoji
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 1991
• Subjects: General Chemistry; baleen whale; baleen whales; toothed whale; toothed whales
• Online Access: http://dx.doi.org/10.1093/jaoac/74.6.943; http://academic.oup.com/jaoac/article-pdf/74/6/943/32454264/jaoac0943.pdf

Abstract Thin-layer isoelectric focusing was applied to the identification of whale (Cetacea) species by using water-soluble sarcoplasmic proteins of skeletal muscles. Twenty-eight samples consisting of 4 species (10 samples) of baleen whales (Mysticeti) and 8 species (18 samples) of toothed whales (Odontoceti) were analyzed. Each sample (approximately 1 g) was electrophoresed with Ampholine PAGplate, pH 3.5-9.5. The electrophoretic profiles were species-specific on the 4 toothed whale species that did not have a marked intra-species difference, and all 4 baleen whale species. However, the profiles were not specific on the 4 other dolphin species, even though they were discriminable from the other 4 toothed whale species. Numerical values of pls and relative peak heights were obtained by densitometric analysis of the isoelectro-focused protein bands. The bands were also species-specific for the 8 toothed whale species mentioned. The values may be applicable to species identification without the need for a standard sample, which may not be readily obtainable. Experiments on test samples of minke and sei whales showed that bloodletting with ice water made the densities of isoelectro-focused bands thinner, although species identification was still possible by using the Inside part of muscles. Heat treatment at below 60°C for 10 min caused little denaturation; at higher temperatures the protein bands were diminished in a temperature-dependent fashion. Therefore, the present isoelectric focusing analysis should be applicable to small samples of whale meat, excluding several species of dolphins.