Lucena Malson Neilson, Garçon Daniela Pereira, Fontes Carlos Frederico Leite, McNamara John Campbell, Leone Francisco Assis
Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, Ribeirão Preto, SP, 14040-901, Brazil.
Universidade Federal do Triângulo Mineiro, Campus Universitário de Iturama, Iturama, Minas Gerais, 38280-000, Brazil.
Mol Cell Biochem. 2017 May;429(1-2):187-198. doi: 10.1007/s11010-017-2946-8. Epub 2017 Feb 11.
Aiming to clarify the mechanism of inhibition of (Na, K)-ATPase activity by polyamines, we examined the effects of exogenous putrescine, spermidine, and spermine on the kinetic behavior of phosphoenzyme-linked partial reactions using a microsomal gill (Na, K)-ATPase from juvenile and adult M. amazonicum, a freshwater palaemonid shrimp. The time course of phosphointermediate formation is greater (0.089 ± 0.006 s) in adults than in juveniles (0.053 ± 0.003 s) for spermidine, but similar to juveniles (0.059 ± 0.004 s) for putrescine. Maximum phosphointermediate formation for the (Na, K)-ATPase from juveniles decreased by 46% and 32% with spermidine and putrescine, respectively. In adults, maximum phosphointermediate levels decreased by 50% and 8%, respectively. For both spermidine and putrescine, dephosphorylation rates were higher for adults than for juveniles, and were higher than in controls without polyamines. Spermine had a negligible effect (<10%) on phosphorylation/dephosphorylation rates of both juvenile and adult enzymes. This is the first report on the effects of polyamines on phosphoenzyme-linked partial reactions in juvenile and adult M. amazonicum gill (Na, K)-ATPases. Our findings suggest that the phosphorylation/dephosphorylation steps of this gill enzyme may be regulated by polyamines during ontogenetic development.
为了阐明多胺抑制（钠，钾）-ATP酶活性的机制，我们使用来自淡水长臂虾亚马逊沼虾幼体和成体的鳃微粒体（钠，钾）-ATP酶，研究了外源腐胺、亚精胺和精胺对磷酸酶连接的部分反应动力学行为的影响。对于亚精胺，成体中磷酸中间体形成的时间进程（0.089±0.006秒）比幼体（0.053±0.003秒）更长，但对于腐胺，其时间进程与幼体相似（0.059±0.004秒）。幼体（钠，钾）-ATP酶的最大磷酸中间体形成量分别被亚精胺和腐胺降低了46%和32%。在成体中，最大磷酸中间体水平分别降低了50%和8%。对于亚精胺和腐胺，成体的去磷酸化速率均高于幼体，且高于无多胺的对照组。精胺对幼体和成体酶的磷酸化/去磷酸化速率的影响可忽略不计（<10%）。这是关于多胺对亚马逊沼虾幼体和成体鳃（钠，钾）-ATP酶中磷酸酶连接的部分反应影响的首次报道。我们的研究结果表明，在个体发育过程中，这种鳃酶的磷酸化/去磷酸化步骤可能受多胺调控。
