Estudos funcionais na hemoglobina de componente simples do peixe faca amazônico, Sternopygos macrurus
L. Garlick, Robert; hJosephJosephJoseph; P. Martin, Joseph; A. Powers, Dennis.
Acta amaz.
; 8(4)1978.
Artículo
en Portugués
| VETINDEX | ID: vti-691445
Summary The complete blood of the water-breathing gymnotid teleost Sternopygus macrurus is 50% saturated with oxygen at 5.2 mm Hg (apparent value) at 30°C in the absence of CO2. Addition of 5.6% CO2 causes a three-fold increase in the value of the apparent P50 The oxygen affinity of the single component hemoglobin at 20°C increases aproxlmately 20 times between pH 5.8 and 8.6 in the absence of ATP. This diference increases a hundred fold In presence of 1 mM ATP. There is a market Root effect the stripped hemoglobin is only 70% saturated with O2 at pH lower than 6 when equilibrated with air. The value of the Hill coefficient, n. is highest between pH 7.0 and 7.5 being close to 1.0 at high pH The value is aproximately 1.5 at low pH In absence of ATP and in the presence of 1 mM ATP. The oxygen kinetics are heterogeneous at all pH values, being more heterogeneous at lower pH. The rate increases substantially with decrease in the pH. The CO combination kinetics as measured by the stopped-flow method are largely homogeneous except at high pH but the combination kinetics after flash photolysis are markedly heterogeneous.
Biblioteca responsable:
BR68.1
Texto completo
Documentos relacionados