Table 1.

Concentrations of amino acids in protein obtained from white muscle and gill tissue of P. brachycephalum and of Z. viviparus

White muscle protein (g 100 g-1) Gill protein (g 100 g-1)
Amino acidsP. brachycephalumZ. viviparusP. brachycephalumZ. viviparus
Cysteine0.010.010.07±0.030.07±0.05
Aspartate1.70±0.151.71±0.120.89±0.071.09±0.27
Hydroxy-prolineNDND0.10±0.050.15±0.05
Threonine0.76±0.080.76±0.030.53±0.060.59±0.16
Serine0.63±0.080.64±0.070.47±0.050.51±0.13
Glutamate2.40±0.202.52±0.171.23±0.091.43±0.33
Proline0.53±0.150.59±0.030.47±0.120.58±0.23
Glycine*0.71±0.070.82±0.090.66±0.080.79±0.30
Alanine0.89±0.080.96±0.080.49±0.040.67±0.16
Valine0.90±0.050.89±0.100.57±0.050.64±0.20
Cysteine0.16±0.080.15±0.010.02±0.010.05±0.02
Methionine0.59±0.090.64±0.050.09±0.030.23±0.11
Isoleucine0.86±0.070.86±0.060.42±0.030.43±0.14
Leucine1.44±0.151.38±0.150.81±0.070.86±0.26
Tyrosine0.44±0.070.49±0.060.23±0.040.27±0.09
Phenylalanine0.74±0.090.74±0.040.42±0.070.48±0.11
Hydroxy-lysineNDND0.02±0.01§0.04±0.01
Ornithin0.04±0.020.03±0.010.01±0.000.01±0.00
Lysine1.54±0.121.56±0.130.74±0.080.82±0.21
Histidine0.38±0.050.43±0.090.31±0.060.27±0.05
Arginine1.07±0.121.07±0.080.57±0.100.70±0.17
Total16.2±1.115.8±1.410.7±2.89.1±0.8
% Fraction of Phe4.6±0.34.7±0.14.5±0.34.7±0.5
  • The ratio of each amino acid to Phe in protein of gill and muscle from both species was calculated to convert nmol of Phe into grams of protein synthesized. The percentage fraction of Phe within the protein was calculated from the ratio of phenylalanine content over the sum of amino acids multiplied by 100.

    ND=not detectable

    Digestion with HCl converts asparagine and glutamine to aspartate and glutamate.

    Data are given as means ± s.d. (N=6, except for gill of Z. viviparus N=5).

  • * A significant difference (P<0.05) between species in white muscle

  • A significant difference (P<0.05) between species in gill

  • only one detectable value out of six determinations

  • § only five detectable values out of six determinations