246
A U m N RIWS
equilibrium of Latimeria hemoglobin. All of these fish possess hemoglobins with large Bohr effects, but the magnitudes differ: that of the
blood of Neocemtodus is highest, followed by Protopterus and Lepidosiren. Although Neoceratodus has the largest Bohr effect and low blood
CO,, and Protopterm has high blood C 0 2 and a smaller Bohr effect, the
diEerence in Bohr effect is not large. These bloods have sigmoid
oxygen equilibria, but the work of Oldham and Riggs (1969) on
Protopterus hemoglobin shows that n is pH dependent, and rises from
1.21.4 below pH 6.5 to 2.0-2.4 above pH 7.5. Of particular interest is
the fact that the two species of Protopterus, P. aethiopicw and P.
annectans, have hemoglobins which differ not only in primary structure
but also in oxygen affinity, which is considerably higher in P. aethiopicus
than in P. annectans (see Fig. 9). This may be associated with the fact
that the P. aethwpicw specimens were obtained from the deep water
lakes of Uganda, whereas the P. annectuns fish were obtained from
marshland in Ghana. Both hemoglobins are composed of at least five
components which are formed from four chains.
In contrast to the hemoglobins of Protopterus, Bonaventura and
Riggs (1969) have found that Latimeria hemoglobin consists largely of
a single component whose oxygen equilibrium shows a substantial Bohr
effect ( r = 0.55 betwecn pH 7 and 8). In addition, the sigmoid coefficient n decreases from 1.6 to 1.1 between pH 7 and 8, in contrast to
Protopterus hemoglobin for which n increases with pH.
ACKNOWLEDGMENTS
I thank Dr. Robert Noble for valuable discussions and for permission to use
certain data prior to publication. I also thank Dr. Shanti Agganval and Dr. Joseph
Bonaventura for reading the review and providing valriable suggestions.
Original work described here was supported in part by NIH Grant CM-05818
and by the Robert A. Welch Foundation.
REFERENCES
Adinolfi, M., Chieffi, G., and Siniscalco, M. (1959). Haemoglobin pattern of the cyclostome Petromyzon pluneri during the course of development. Nature 184,
1325.
Albers, C., and Pleschka, K. (1967). Effect of temperature on CO, transport in
elasmobranch blood. Resp. Physiol. 2, 261.
Anderson, S., and Antonini, E. (1968). The binding of carbon monoxide by human
hemoglobin. 3. B i d . Chcm. 243, 2918.
Antonini, E. ( 1965). Interrelationship between structure and function in hemoglobin and myogloliin. Physiol. Reo. 45, 123.
Antonini, E., Wyman, J., Bellelle, L., Rumen, N., and Siniscalco, M. (1964). The
oxygen equilibrium of some lamprey hemoglobins. Arch Biochem. Biophy~. 105,
404.
A U m N RIWS
equilibrium of Latimeria hemoglobin. All of these fish possess hemoglobins with large Bohr effects, but the magnitudes differ: that of the
blood of Neocemtodus is highest, followed by Protopterus and Lepidosiren. Although Neoceratodus has the largest Bohr effect and low blood
CO,, and Protopterm has high blood C 0 2 and a smaller Bohr effect, the
diEerence in Bohr effect is not large. These bloods have sigmoid
oxygen equilibria, but the work of Oldham and Riggs (1969) on
Protopterus hemoglobin shows that n is pH dependent, and rises from
1.21.4 below pH 6.5 to 2.0-2.4 above pH 7.5. Of particular interest is
the fact that the two species of Protopterus, P. aethiopicw and P.
annectans, have hemoglobins which differ not only in primary structure
but also in oxygen affinity, which is considerably higher in P. aethiopicus
than in P. annectans (see Fig. 9). This may be associated with the fact
that the P. aethwpicw specimens were obtained from the deep water
lakes of Uganda, whereas the P. annectuns fish were obtained from
marshland in Ghana. Both hemoglobins are composed of at least five
components which are formed from four chains.
In contrast to the hemoglobins of Protopterus, Bonaventura and
Riggs (1969) have found that Latimeria hemoglobin consists largely of
a single component whose oxygen equilibrium shows a substantial Bohr
effect ( r = 0.55 betwecn pH 7 and 8). In addition, the sigmoid coefficient n decreases from 1.6 to 1.1 between pH 7 and 8, in contrast to
Protopterus hemoglobin for which n increases with pH.
ACKNOWLEDGMENTS
I thank Dr. Robert Noble for valuable discussions and for permission to use
certain data prior to publication. I also thank Dr. Shanti Agganval and Dr. Joseph
Bonaventura for reading the review and providing valriable suggestions.
Original work described here was supported in part by NIH Grant CM-05818
and by the Robert A. Welch Foundation.
REFERENCES
Adinolfi, M., Chieffi, G., and Siniscalco, M. (1959). Haemoglobin pattern of the cyclostome Petromyzon pluneri during the course of development. Nature 184,
1325.
Albers, C., and Pleschka, K. (1967). Effect of temperature on CO, transport in
elasmobranch blood. Resp. Physiol. 2, 261.
Anderson, S., and Antonini, E. (1968). The binding of carbon monoxide by human
hemoglobin. 3. B i d . Chcm. 243, 2918.
Antonini, E. ( 1965). Interrelationship between structure and function in hemoglobin and myogloliin. Physiol. Reo. 45, 123.
Antonini, E., Wyman, J., Bellelle, L., Rumen, N., and Siniscalco, M. (1964). The
oxygen equilibrium of some lamprey hemoglobins. Arch Biochem. Biophy~. 105,
404.