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Tsong, T. Y. (1977). Conformational relaxations of urea- and guanidine hydrochloride-unfolded ferricytochrome c. J Biol Chem, 252(24), 8778–8780.
Abstract: Several recent studies of protein the unfolded proteins. In urea- and guanidine HCl-unfolded ferricytochrome c (horse heart), an acid-induced spin state transformation of the heme group has been detected by the heme absorptions, Trp-59 fluorescence, and the intrinsic viscosity of protein. Kinetics of this second conformational transition, by the temperature jump and stopped flow methods, are complex. One rapid reaction (tau1), pH-independent, occurs in a 50-mus range; the second reaction (tau2), in a 1-ms range, depends linearly upon pH and is faster at the alkaline side; a third reaction (tau3), in a 1-s range, shows a sigmoidal transition at pH 5.1 and is faster at the acidic side. The results are consistent with a kinetic scheme which involves protein conformational changes in the transformation of the heme coordination state. The kinetics, along with previous equilibrium studies, indicate that ligand or charge interactions within a protein molecule are not completely prohibited even in strongly denaturing conditions, such as in high concentrations of urea and guanidine HCl. Thus, local structures of peptide chain associated with these interactions can exist in the unfolded protein.
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Kratzer, D. D., Netherland, W. M., Pulse, R. E., & Baker, J. P. (1977). Maze Learning in Quarter Horses. J. Anim Sci., 45(4), 896–902.
Abstract: A two-compartment maze providing a single left- or right-side choice was used to test maze-learning ability in 37 quarter horses. Preference for left- or right-side choices varied among the horses. The taller and thinner horses tended to go left. The horses showed learning ability based on decreases in latency and decreases in errors as trials progressed in a right-side escape pattern. The rate of learning an opposite escape pattern, left-side escape, was faster but owing to the large number of errors occurring when the pattern was reversed, the level of errors did not reduce to a level comparable to that achieved in the right-side escape pattern until adverse stimuli were presented in the blind compartment. Heavier horses took longer to escape from the maze when adverse stimuli were presented. Differences in learning ability for horses fed various levels of dietary protein were not consistent. N1 -
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Nitschelm D, H. V. D. C. (1977). The influence of chlormadinone acetate treatment on the concentration of some stereoids in the blood, on the ovarian activity and on.. Tijdschr Diergeneesk, 102, 861–872.
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Knill, L. M., Eagleton, R. D., & Harver, E. (1977). Physical optics of the equine eye. Am J Vet Res, 38(6), 735–737.
Abstract: The equine eye was treated as a general lens system and calculations were done to determine image position in relation to the retina for objects at a distance of infinity, 100 m, and 1 m. The retina is 19.1 mm behind the posterior surface of the lens; therefore, the image appears 14.6 mm posterior to the retina at infinity and at 100 m, and 16.3 mm at 1-m distance on a horizontal axis. The animals studied were hyperopic. It is evident that the horse must move its head or eye, or both, for optimal visual acuity. At the same time, some objects in the total field of vision are imperceptible or indistinct.
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Klingel H,. (1977). Communication in Perissodactyla. (pp. 715–727,).
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Seyfarth, R. M. (1977). A model of social grooming among adult female monkeys. J. Theor. Biol., 65(4), 671–698.
Abstract: Grooming networks among adult female monkeys exhibit two similar features across a number of different species. High-ranking animals receive more grooming than others, and the majority of grooming occurs between females of adjacent rank. A theoretical model which duplicates these features is presented, and the properties of the model are used to explain the possible causation and function of female grooming behaviour. The model illustrates how relatively simple principles governing the behaviour of individuals may be used to explain more complex aspects of the social structure of non-human primate groups.
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Alexander, F. (1977). The effect of diuretics on the faecal excretion of water and electrolytes in horses. Br J Pharmacol, 60(4), 589–593.
Abstract: 1. The effect on plasma, urinary and faecal electrolytes of frusemide and hydrochlorthiazide was measured in ponies, mean weight 180 kg. 2. The rapid loss in urine of large quantities of sodium had only a small effect on plasma sodium concentration. 3. Faecal sodium excretion was increased substantially after the administration of frusemide. 4. Frusemide increased faecal potassium during the 48 h following administration and faecal water in the 24/48 h period. It also produced a hypopotassaemia. 5. Hydrochlorthiazide increased faecal chloride during the 24 h after administration. 6. Frusemide increased the intestinal transit time of both liquid (polyethylene glycol) and particulate (Cr2O3) markers.
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Bard Jbl,. (1977). A unity underlying the different zebra stripping patterns. J Zool Lond, 183, 527–539.
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Kihara, H., Nakatani, H., Hiromi, K., & Hon-Nami, K. (1977). Kinetic studies on redox reactions of hemoproteins. I. Reduction of thermoresistant cytochrome c-552 and horse heart cytochrome c by ferrocyanide. Biochim Biophys Acta, 460(3), 480–489.
Abstract: The oxidation-reduction reaction of horse heart cytochrome c and cytochrome c (552, Thermus thermophilus), which is highly thermoresistant, was studied by temperature-jump method. Ferrohexacyanide was used as reductant. (Formula: see text.) Thermodynamic and activation parameters of the reaction obtained for both cytochromes were compared with each other. The results of this showed that (1) the redox potential of cytochrome c-552, + 0.19 V, is markedly less than that of horse heart cytochrome c. (2) deltaHox of cytochrome c-552 is considerably lower than that of horse heart cytochrome c. (3) deltaSox and deltaSred of cytochrome c-552 are more negative than those of horse heart cytochrome c. (4) kred of cytochrome c-552 is much lower than that of horse heart cytochrome c at room temperature.
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Kihara, H., Nakatani, H., Hiromi, K., Hon-Nami, K., & Oshima, T. (1977). Kinetic studies on redox reactions of hemoproteins. I. Reduction of thermoresistant cytochrome c-552 and horse heart cytochrome c by ferrocyanide. Biochimica et Biophysica Acta (BBA) – Bioenergetics, 460(3), 480–489.
Abstract: The oxidation-reduction reaction of horse heart cytochrome c and cytochrome c (552, Thermus thermophilus), which is highly thermoresistant, was studied by temperature-jump method. Ferrohexacyanide was used as reductant. Thermodynamic and activation parameters of the reaction obtained for both cytochromes were compared with each other. The results of this showed that (1) the redox potential of cytochrome c-552,+0.19 V, is markedly less than that of horse heart cytochrome c. (2) [up triangle, open]Hox++ of cytochrome c-552 is considerably lower than that of horse heart cytochrome c. (3) [up triangle, open]Hox++ and [up triangle, open]Sred++ of cytoochrome c-552 are more negative than those of horse heart cytochrome c. (4) kred of cytochrome c-552 is much lower than that of horse heart cytochrome c at room temperature.
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