Arp A J, Doyle M L, Di Cera E, Gill S J
Department of Biology, San Francisco State University, CA 94132.
Respir Physiol. 1990 May-Jun;80(2-3):323-34. doi: 10.1016/0034-5687(90)90092-d.
Riftia pachyptila vascular blood and coelomic fluid contain two hemoglobin molecules that differ in their distribution and physical properties. The present study of the two isolated hemoglobins shows that both have an extremely high affinity for oxygen, but differ in their oxygenation characteristics. FI, the larger molecular weight (Mr) fraction (1,700,000), has a lower oxygen affinity, a well defined pH Bohr effect, and high cooperativity of oxygen binding. FII, the lower Mr fraction (400,000) has a higher oxygen affinity, no pH Bohr effect, and reduced cooperativity of oxygen binding. Both hemoglobins show marked effects of temperature on oxygen binding, and no effect of heme concentration or the presence of sulfide on oxygen affinity. The differences in the oxygenation properties and distribution of the two hemoglobins in the body fluids of Riftia pachyptila may allow them to play different roles in oxygen transport and storage for the animal which lives in the variable environment of the hydrothermal vents.
巨型管虫的血管血液和体腔液中含有两种血红蛋白分子，它们在分布和物理性质上存在差异。对这两种分离出的血红蛋白的当前研究表明，它们对氧气都具有极高的亲和力，但在氧合特性上有所不同。FI是分子量较大（Mr）的组分（1,700,000），具有较低的氧亲和力、明确的pH玻尔效应以及较高的氧结合协同性。FII是分子量较低（Mr）的组分（400,000），具有较高的氧亲和力、无pH玻尔效应以及较低的氧结合协同性。两种血红蛋白都显示出温度对氧结合有显著影响，而血红素浓度或硫化物的存在对氧亲和力没有影响。巨型管虫体液中两种血红蛋白的氧合特性和分布差异可能使它们在生活于热液喷口多变环境中的动物的氧气运输和储存中发挥不同作用。
