Data/hora: 03/06/2024 02:57:29

Provedor de dados: | 42
País: | Brazil
Título: | Energy interconversion by the sarcoplasmic reticulum Ca2+-ATPase: ATP hydrolysis, Ca2+ transport, ATP synthesis and heat production
Autores: | MEIS,LEOPOLDO DE.
Data: | 2000-09-01
Ano: | 2000
Palavras-chave: | Ca2+-ATPase; Ca2+ transport; Energy interconversion; ATP hydrolysis; Heat production; Sarcoplasmic reticulum.
Resumo: | The sarcoplasmic reticulum of skeletal muscle retains a membrane bound Ca2+-ATPase which is able to interconvert different forms of energy. A part of the chemical energy released during ATP hydrolysis is converted into heat and in the bibliography it is assumed that the amount of heat produced during the hydrolysis of an ATP molecule is always the same, as if the energy released during ATP cleavage were divided in two non-interchangeable parts: one would be converted into heat, and the other used for Ca2+ transport. Data obtained in our laboratory during the past three years indicate that the amount of heat released during the hydrolysis of ATP may vary between 7 and 32 Kcal/mol depending on whether or not a transmembrane Ca2+ gradient is formed across the sarcoplasmic reticulum membrane. Drugs such as heparin and dimethyl sulfoxide are able to modify the fraction of the chemical energy released during ATP hydrolysis which is used for Ca2+ transport and the fraction which is dissipated in the surrounding medium as heat.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652000000300010
Editor: | Academia Brasileira de Ciências
Relação: | 10.1590/S0001-37652000000300010
Formato: | text/html
Fonte: | Anais da Academia Brasileira de Ciências  v.72 n.3 2000
Fonte: | info:eu-repo/semantics/openAccess