2175 



Menzel, Winston. 1979. 



Claras and snails [Mollusca: Pelecypoda (except oysters) and Gastropoda] . 



Chapter 12 in Pollution Ecology of Estuarine Invertebrates. Academic 

 Press, Inc., New York, N.Y.: 371-396. 



This review paper has numerous references to Meroenaria meroenaria and M. 

 aampechiensis , all of which are abstracted elsewhere in this bibliography. 

 - J.L.M. 



2176 



Merrick, Jacqueline P., and William H. Johnson. 1977. 



Solubility properties of a-reduced paramyosin. Biochem. 16(10): 2260-2264. 



The reduced form of a-paramyosin is what is found in living adductor muscles 

 of molluscs. In contrast to the solubility profile of B-paramyosin, the a- 

 preparation showed a rapid, almost linear decrease in solubility over the 

 ionic strength range 0.35 to 0.25 at neutral pH. Solubility in this range 

 was further decreased by presence of physiologically small amounts of Ca 

 ion. Lactate ion, which can accumulate during anaerobic glycolysis in mol- 

 luscan muscles, also decreases the solubility at a level of 50 mM. The type 

 of paracrystal formed by a-paramyosin differs greatly from those of 6- 

 paramyosin and paracrystal formed in the presence of lactate differs from 

 those formed in buffer solutions. Reduced a-paramyosin is more sensitive to 

 the above parameters than preparations made without reducing agents. The pH 

 and ionic strength ranges in which greatest change in solubility behavior 

 occurs are physiologic, as are Ca and lactate ion levels effective in in- 

 creasing intermolecular interactions. A model is proposed for a-paramyosin 

 in which the extra 5% presumably removed in 3-preparations is a "sticky 

 head" which protrudes from one end of the molecule and confers on it an 

 increased tendency for interaction, particularly at physiological ionic 

 strengths. Such molecules would be capable of promoting interactions be- 

 tween thick filaments which contain them, providing a means of accounting 

 for the pH dependent stiffness observed in glycerinated preparations of 

 molluscan catch muscles. - modified authors' abstract - J.L.M. 



2177 



Mitterer, Richard Max. 1966. 



Amino acid and protein geochemistry in mollusk shells. Ph.D. Thesis, 

 Florida State Univ. Dissert. Abstr. , Sect. B. Geology, Apr. -June 1967, 

 vol. 27: 3994-B. 



Analysis of modern Meroenaria meroenaria shells from various environments 

 shows little variability in amino acid composition of the organic matrix 

 caused by environmental effects. All amino acids were found in lower 

 amounts with increasing ages of fossil Mercenaria shells. Some amino acids 

 increase in relative abundance with increasing age of shell. Alanine, pro- 

 line, glutamic acid, glycine, valine, leucine, and aspartic acid are found 

 in greatest abundance in Middle Miocene shells. Certain ratios such as 

 Glu/Asp, Alloiso/Iso, Phe/Tyr, and Orn/Arg increase consistently with 

 increasing ages of shells. These could possible provide a relative age- 

 dating method. Application of Vallentyne's theoretical results on time- 

 temp relations of amino acids to the data reported herein yields a maximum 

 continuous diagenetic temperature of 14°C for the Middle Miocene Calvert 

 Formation of Maryland. Temps obtained for Upper Miocene Duplin Formation 

 and its equivalents are 18°C for North Carolina and North Florida and 20°C 

 for South Florida. The presence of certain non-protein amino acids such as 

 a-aminobutyric acid, y-aminobutyric acid, and 6-alanine, and high ammonia 

 concentrations in the fossils shows that decarboxylation and deamination 

 reactions are occurring within the shells. - J.L.M. 



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