Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto/Universidade de São Paulo, SP, Brazil.
Instituto de Biologia/Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
Comp Biochem Physiol B Biochem Mol Biol. 2024 Aug-Sep;273:110987. doi: 10.1016/j.cbpb.2024.110987. Epub 2024 May 11.
The Macrobrachium amazonicum complex is composed of at least the Macrobrachium amazonicum and Macrobrachium pantanalense species, with the latter described from specimens originally identified as part of an endemic M. amazonicum population in the Brazilian Pantanal region. While there may be a reproductive barrier between these two Macrobrachium species, both are phylogenetically close, with small genetic distance. However, there is currently no available biochemical information of Macrobrachium pantanalense (Na, K)-ATPase. Here, we report the kinetic characteristics of the gill (Na, K)-ATPase in two populations of M. pantanalense from Baiazinha Lagoon (Miranda, MS, Brazil) and Araguari River (Uberlândia, MG, Brazil), and compare them with Macrobrachium amazonicum populations from the Paraná-Paraguay River Basin. (Na, K)-ATPase activities were 67.9 ± 3.4 and 93.3 ± 4.1 nmol Pi min mg protein for the Baiazinha Lagoon and Araguari River populations, respectively. Two ATP hydrolyzing sites were observed for the Araguari River population while a single ATP site was observed for the Baiazinha Lagoon shrimps. Compared to the Araguari River population, a 3-fold greater apparent affinity for Mg and Na was estimated for the Baiazinha Lagoon population, but no difference in K affinity and ouabain inhibition was seen. The kinetic differences observed in the gill (Na, K)-ATPase between the two populations of M. pantanalense, compared with those of various M. amazonicum populations, highlight interspecific divergence within the Macrobrachium genus, now examined from a biochemical perspective.
亚马逊沼虾复合体由至少亚马逊沼虾和潘塔纳尔沼虾组成，后者是从最初被鉴定为巴西潘塔纳尔地区特有亚马逊沼虾种群一部分的标本中描述的。虽然这两个Macrobrachium 物种之间可能存在生殖障碍，但它们在系统发育上非常接近，遗传距离很小。然而，目前尚无潘塔纳尔沼虾的生化信息（Na，K）-ATPase。在这里，我们报告了来自米拉达巴伊扎因哈泻湖（巴西米纳斯吉拉斯州米兰达）和乌鲁布兰迪亚阿瓜里乌里河（巴西米纳斯吉拉斯州乌鲁布兰迪亚）的两个潘塔纳尔沼虾种群的鳃（Na，K）-ATPase的动力学特征，并将其与来自巴拉那-巴拉圭河流域的亚马逊沼虾种群进行了比较。（Na，K）-ATPase 活性分别为 67.9±3.4 和 93.3±4.1 nmol Pi min mg 蛋白，来自巴伊扎因哈泻湖和阿瓜里乌里河的种群。阿瓜里乌里河种群观察到两个 ATP 水解位点，而巴伊扎因哈泻湖虾只观察到一个 ATP 位点。与阿瓜里乌里河种群相比，巴伊扎因哈泻湖种群对 Mg 和 Na 的表观亲和力估计增加了 3 倍，但对 K 的亲和力和哇巴因抑制没有差异。与各种亚马逊沼虾种群相比，潘塔纳尔沼虾两个种群的鳃（Na，K）-ATPase 的动力学差异突出了 Macrobrachium 属内的种间差异，现在从生化角度进行了研究。
