Muscle Proteins of the CoelacanthLatimeria ChalumnaeSmith

Abstract

Although the anatomy of the coelacanth muscles has been examined very thoroughly, their protein composition has, until recently, not been investigated. Thanks, however, to the 1972 British–French–American expedition to the Comores, frozen material has been made available and some results on myoglobin and four glycolytic enzymes have already been published. We have carried out a comparison of the sarcoplasmic proteins of red and white muscle by starch-gel electrophoresis. The ninhydrin-positive dialysable constituents and the myofibrillar proteins of white muscle have also been examined.A few puzzling results obtained with the white muscle extracts have been related to the occurrence of o.1 M ammonia, due presumably to the splitting of urea by a bacterial urease, and to an alteration of the active thiol groups of GAPDH and PK. If due account is taken of these unusual post-mortem changes, the extractability of the proteins and their properties are strikingly similar to those of teleosteans. The comparison of the sarcoplasmic proteins of white and red muscle by starch-gel electrophoresis revealed also that the differentiation observed in the coelacanth was similar to that occurring in the carp. A study of the low-molecular-weight proteins, or parvalbumins, of white muscle and of the myofibrillar proteins also shows the expected differences between the two muscle types.The only abnormal features observed in this study were the high concentration of parvalbumins, 1.5–2 times that found in other species examined, and the occurrence of an unusual globulin fraction which was easily extracted at ionic strength 0.5 and insoluble at ionic strength 0.35 and neutral pH.

Enzyme variation inChthamalus stellatusandChthamalus montagui(Crustacea: Cirripedia): evidence for the presence ofC. montaguiin the Adriatic

“…PK, PGK, ARK and EN were detected by the reduction of NADH fluorescence under ultraviolet light. References for the specific staining reactions are: GAPDH, PGK, PGAM, ALD (Scopes, 1968); MDH, SOD, EN (Harris & Hopkinson, 1976); PGM (Hamoir et al 1973); MPI, GPI (Dando, 1974). The PK stain contained 25 mM ADP, 1 raM phosphoenolpyruvate, o-i mM NADH, 6-6 mM-KHCO 3 , 125 mM-KCl, 5 mM-MgCl 2 , 9 u. rabbit muscle LDH, 100 mM triethanolamine adjusted to pH 70 with HC1.…”

Enzymes of the coelacanth Latimeria chalumnae evidenced by starch gel electrophoresis

“…Brown & Brown (1967) first disclosed that coelacanth liver contained urea at a level of 1.7 percent (wet weight), comparable to that found in elasmobranchs such as sharks, skates, and rays (see also Pickford & Grant 1967). Since that time various enzymes of the coelacanth have been studied (Kolb & Harris 1972, Hamoir et al 1973, Goldstein et al 1973, Kolb et al 1974, Solomon & Brown 1976, Ferris & Whitt 1978, Fisher & Whitt 1979, Rasmussen 1979, Webb & Brown 1980, Mommsen & Walsh 1989). …”

“…We saw activity for this enzyme in all tissues tested at two isoloci. Only two isoloci for GPI were detected, in contrast to four previously reported by Hamoir et al (1973). Activity for GPI was seen largely in the male, although in kidney from the female, a pattern unlike that of the male was seen.…”

“…Three isoloci were seen in esterase, Whitt (1979). Hamoir et al (1973) found three with several tissues specific for only one of the loci. Table 1 are noted above each of the drawings showing the structure and migration distance of the loci in millimeters.…”