. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 156 L. E. BURNETT ET 5 8.! pH Figure 2. The effect of temperature on hemocyanin oxygen affinity (log Pso) and cooperativity (n50) as a function of pH in the ahalone Millions corrugata, the chiton Stenoplax conspicua, the xanthid crab Eurytium albidigilum. and the horseshoe crab Limuluspolyphemus. P50 and n50 were determined at 5°C (a), 15°C (A), 25°C (•), and 35°C (O), except as noted for L polyphemus. higher temperatures. In L. polyphemus minimal sensitiv- ity was found in the 15 to 25°C range. Later it was
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 156 L. E. BURNETT ET 5 8.! pH Figure 2. The effect of temperature on hemocyanin oxygen affinity (log Pso) and cooperativity (n50) as a function of pH in the ahalone Millions corrugata, the chiton Stenoplax conspicua, the xanthid crab Eurytium albidigilum. and the horseshoe crab Limuluspolyphemus. P50 and n50 were determined at 5°C (a), 15°C (A), 25°C (•), and 35°C (O), except as noted for L polyphemus. higher temperatures. In L. polyphemus minimal sensitiv- ity was found in the 15 to 25°C range. Later it was found that this phenomenon is due to complete insensitivity between 20 and 25°C and that the AH value for 15-20°C is unexceptional (C. P. Mangum and J. Ricci, in prep.). The values for cooperativity of the arthropod Hcs show some tendency to increase in the middle and upper ends of the pH range examined (Figs. 1, 2). In C. antho- m'/and H. corrugata the pH dependence of cooperativity appears to increase with temperature; in the other species there is no clear trend. In general, however, cooperativity is influenced very little by either pH or temperature. Like other polyplacophoran Hcs {, Mangum and Burnett, 1986), S. conspicua He exhibits very little cooperativity, a feature that does not change with temperature (Fig. 2). Above 5°C, cooperativity of H. corrugata He decreases with decreasing pH (Fig. 2), a finding that agrees with Ainslie's (1980) report of a decrease in n50 with increas- ing PCo2 of three other Haliotis Hcs. Otherwise tempera- ture has no clear effect. Dialyzing C. antkonyi He against 500 mmol/1 NaCl and 1 mmol/1 EGTA caused large decreases in 02 affinity (cf. Figs. 1, 4). The present results indicate that Ca+2 has an effect on temperature sensitivity. The temperature sensi- tivity of the He dialyzed against a calcium-free saline and EGTA was slightly less than the controls between 5 and 25°C but much greater than the controls between 25 and 35&
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
