238
AUSTEN RIGGS
reduction so the possibility of denatured artifacts cannot be excluded.
The data of Antonini et al. (1964) on the unfractionated Petromyzon
marinus hemolyzate were obtained at a much lower protein concentration than the data of Briehl (1963) and Wald and Riggs (1951). When
the latter data are adjusted for this difference according to the concentration dependence found by Brichl, all three sets of data are in substantial
agreement. Briehl showed that an increase in concentration from about
0.1 to 3.6% was accompanied by an increase in log P,,, from about 0.8 to
2.7-an eightyfold increase in 0, pressure required for half-satur a t’ ion.
This enormous effect of concentration should serve warning to those
inclined to impart physiological significance to a value obtained from
an experiment at a single (dilute) protein concentration. Unfortunately,
virtually all published data on hemoglobin solutions of fish hemoglobins
do not consider the possible importancc of concentration dependence.
Such “single-value” studies may be of considerable significance in other
ways, but they cannot be used to imply anything about the physiological
adaptation of thc hemoglobin in its in rjivo function.
Rumen and Love (1963b) dcmonstrated that the differcnt componrnts of lamprey hemoglobin, when mixed and deoxygenated, will
form hybrid molecules. Component 1 can form a dimer with components
2, 4, and 5, and component 3 will combinc with 4 and with 5 to form
tetramers of the form (3-4)? and (3-5),. Appraisal of the physiological
importance of such complexes must await determination of the oxygen
equilibria of the appropriate mixtures. This would only be significant
if different components occurred in the samc cell.
Manwell (1958c, 1963b) has measured the oxygen equilibria of the
hemoglobins (both in solution and in red cells) of the adult and ammocoete larva of Petromyzon mnrinus, and of the Atlantic and Pacific
hagfishes, hlyxine glutinosa, and Eptntretus ( = Polistotrema ) stouti. He
states that no significant difference occurs in cyclostomes betwecw oxygen
equilibria obtained in solution and in rcd cells. As discussed in Section
111, E, 2, it seems that considcrations of the Donnan equilibrium would
require that a differencc exists between cell and solution in any hemoglobin with a large Bohr effect.
In contrast to the lamprey hemoglobins, those of the hagfishes are
devoid of significant Bohr effect (except below pH 6.5), so equality of
measurements of cell and solution is possiblc with these fish. The hagfish hemoglobins also differed from those of the lampreys in oxygen
affinity: Eptatretus hernoglobin in solution had a P,,, value of only 1.8
mm at 18”C, and 3-4 mm in cells, in contrast to va1uc.s 3-5 times as
great for the lampreys.
AUSTEN RIGGS
reduction so the possibility of denatured artifacts cannot be excluded.
The data of Antonini et al. (1964) on the unfractionated Petromyzon
marinus hemolyzate were obtained at a much lower protein concentration than the data of Briehl (1963) and Wald and Riggs (1951). When
the latter data are adjusted for this difference according to the concentration dependence found by Brichl, all three sets of data are in substantial
agreement. Briehl showed that an increase in concentration from about
0.1 to 3.6% was accompanied by an increase in log P,,, from about 0.8 to
2.7-an eightyfold increase in 0, pressure required for half-satur a t’ ion.
This enormous effect of concentration should serve warning to those
inclined to impart physiological significance to a value obtained from
an experiment at a single (dilute) protein concentration. Unfortunately,
virtually all published data on hemoglobin solutions of fish hemoglobins
do not consider the possible importancc of concentration dependence.
Such “single-value” studies may be of considerable significance in other
ways, but they cannot be used to imply anything about the physiological
adaptation of thc hemoglobin in its in rjivo function.
Rumen and Love (1963b) dcmonstrated that the differcnt componrnts of lamprey hemoglobin, when mixed and deoxygenated, will
form hybrid molecules. Component 1 can form a dimer with components
2, 4, and 5, and component 3 will combinc with 4 and with 5 to form
tetramers of the form (3-4)? and (3-5),. Appraisal of the physiological
importance of such complexes must await determination of the oxygen
equilibria of the appropriate mixtures. This would only be significant
if different components occurred in the samc cell.
Manwell (1958c, 1963b) has measured the oxygen equilibria of the
hemoglobins (both in solution and in red cells) of the adult and ammocoete larva of Petromyzon mnrinus, and of the Atlantic and Pacific
hagfishes, hlyxine glutinosa, and Eptntretus ( = Polistotrema ) stouti. He
states that no significant difference occurs in cyclostomes betwecw oxygen
equilibria obtained in solution and in rcd cells. As discussed in Section
111, E, 2, it seems that considcrations of the Donnan equilibrium would
require that a differencc exists between cell and solution in any hemoglobin with a large Bohr effect.
In contrast to the lamprey hemoglobins, those of the hagfishes are
devoid of significant Bohr effect (except below pH 6.5), so equality of
measurements of cell and solution is possiblc with these fish. The hagfish hemoglobins also differed from those of the lampreys in oxygen
affinity: Eptatretus hernoglobin in solution had a P,,, value of only 1.8
mm at 18”C, and 3-4 mm in cells, in contrast to va1uc.s 3-5 times as
great for the lampreys.