Permyakov E A, Kreimer D I
Gen Physiol Biophys. 1986 Aug;5(4):377-89.
Data obtained by the intrinsic protein fluorescence technique showed that, in addition to Ca2+ and Mg2+ ions, bovine alpha-lactalbumin also binds physiologically significant Na+ and K+ ions, the nucleotides ATP, ADP, UTP, UDP and UDP-galactose. The release of the bound Ca2+ ions from the protein in a medium modelling physiological conditions (containing Mg2+, Na+, K+, ATP and ADP in physiological concentrations) induced a transition of the protein from the native state of the Ca2+-loaded form to a state which is a mixture of native and and thermally changed states of the apo- and metal bound forms. Any variations in temperature result in changes in the populations of these states. This may be associated with some Ca2+ and temperature dependent regulation of the protein function. Variations of pH within the physiological limits had little influence on the conformation of both Ca2+-loaded and Ca2+-free alpha-lactalbumin.
通过内在蛋白荧光技术获得的数据表明，除了Ca2+和Mg2+离子外，牛α-乳白蛋白还能结合具有生理意义的Na+和K+离子、核苷酸ATP、ADP、UTP、UDP以及UDP-半乳糖。在模拟生理条件的介质（含有生理浓度的Mg2+、Na+、K+、ATP和ADP）中，蛋白质结合的Ca2+离子释放会导致蛋白质从Ca2+负载形式的天然状态转变为一种混合状态，该混合状态包含脱辅基和金属结合形式的天然状态与热变化状态。温度的任何变化都会导致这些状态的比例发生变化。这可能与蛋白质功能的某些Ca2+和温度依赖性调节有关。生理范围内pH值的变化对Ca2+负载和无Ca2+的α-乳白蛋白的构象影响很小。
