Jones (11) recently showed that the muscle tissues of cod contain anserinase, an enzyme which hydrolyzes the dipeptide anserine to its constituent amino acids, I-methylhistidine and p-alanine ; and that the enzyme continues to act in sterile cod flesh during storage. Since such a reaction offers promise of developing methods for following fish handling practices independent of microbiological spoilage, it was of interest to us to determine whether anserinase occurs in tuna. Preliminary observations indicated that the various tuna species contained no detectable anserinase activity, but that they did contain unexpectedly large amounts of anserine, approaching in some samples 1% of the wet weight of the tissue. The survey reported in this paper was then undertaken in order to obtain more complete information than was available on the distribution of anserine and related imidazole compounds in the muscles of aquatic animals. Previous work in this field and Yudaev's observations (30) in particular were reviewed by Shewan (18) in 1951. Subsequent information has been limited to the semi-quantitative observations provided by Shewan et al. (19), and Shewan (20,Zl).The elegant ion-exchange method developed by Davey ( 4 ) for determining carnosine, anserine, histidine and methylhistidine made possible analyses which had previously been time-consuming and of doubtful accuracy. E X P E R I M E N T A LMaterials. The samples of tissue analyzed were obtained from a number of sources. W e are indebted to the U. S. Fish and Wildlife Service for frozen samples of several marine and all of the fresh water fish. F. E. Booth Company, Inc., furnished several tuna.One sample of king salmon and one of lingcod muscle were excised and frozen at sea immediately after the fish mere caught. The leopard shark was a fresh specimen within a few hours of catch. Fresh whalc meat was obtained from the Del Monte Fishing Company. Numerous other samples were obtained from local fish markets.Preparation of extracts. Five grams of muscle were extracted with 50 ml. of 1% picric acid in a Waring blender as described by Hamilton (8). The extract was filtered (suction) and with the washings was freed of picric acid by passing it through a Dowex-2 column as described by Tallan et al. (27). The effluent was evaporated to small volume in a rotary evaporator, diluted quantitatively to 5 to 25 ml., and either analyzed immediately or held in the frozen state until needed. Those extracts which were not entirely clear after the step of concentration were treated with Celite and refiltered before adjustment to final volume. An extract obtained with 80% alcohol was also found to contain the imidazole compounds quantitatively ( Table 2).Analytical methods. The ion-exchange column procedure of Davey ( 4 ) was used except that the column length was extended from 50 cm. to 65 cm. Column preparation (Dowex 50-X4) and operation procedures were those of Moore and Stein (15). One ml. fractions were obtained at the rate of 5 per hour with an automatic collector. Elution

The critical concentration (cmc) of sodium dodecyl sulfate at various NaCl concentrations can be followed by the increasing fluorescent intensity of 2-p-toluidinylnaphthalene-6-sulfonate (TNS). The thermodynamic parameters of the interaction of TNS and the SDS micelle have been obtained. Binding is exothermic and involves a positive entropy change. The negative value of enthalpy predominately contributes to the negative free energy of binding between TNS and the SDS micelle. The salt (NaCl) increases the association constant between TNS and micelle of SDS by increasing the positive entropy change. The results suggest that the binding force between TNS and the micelle of SDS is hydrophobic. The nature of hydrophobic fluorescent probe binding with proteins is discussed.

The problem of copper casse formation in wines has been studied intensively both here and abroad (3, 4,7,8,9,14,15, 16,17,25,26) since its first recognition by Carles in 1908 ( 3 ) . It has been ascribed to formation of cuprous sulfite (8,25), mixed cuprous and cupric sulfites (20), copper polypeptides (17), and cupric sulfide (26). On the basis of chemical equilibrium considerations (21) the most plausible theory was that proposed by .The mechanism of copper came formation as given by was not unequivocably demonstrated. He assumed the reactions which may take place to be as follows:1) 2) 3) 4) GUS Flocculation (Haze formation)Cu' f + R H + Cu+ +R + H + (Reduction of cupric ions) 6 Cu+ + 6 H+ + SO2 + 6 Cuf + + HZS + 2 H20 (Reduction of sulfur dioxide) Cu+ + + H2S + CuS + 2 H+ (Formation of insoluble cupric sulfide) 9

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