Thermal activation of ‘allosteric-like’ large-scale motions in a eukaryotic Lactate Dehydrogenase
نویسندگان
چکیده
Conformational changes occurring during the enzymatic turnover are essential for the regulation of protein functionality. Individuating the protein regions involved in these changes and the associated mechanical modes is still a challenge at both experimental and theoretical levels. We present here a detailed investigation of the thermal activation of the functional modes and conformational changes in a eukaryotic Lactate Dehydrogenase enzyme (LDH). Neutron Spin Echo spectroscopy and Molecular Dynamics simulations were used to uncover the characteristic length- and timescales of the LDH nanoscale motions in the apo state. The modes involving the catalytic loop and the mobile region around the binding site are activated at room temperature, and match the allosteric reorganisation of bacterial LDHs. In a temperature window of about 15 degrees, these modes render the protein flexible enough and capable of reorganising the active site toward reactive configurations. On the other hand an excess of thermal excitation leads to the distortion of the protein matrix with a possible anti-catalytic effect. Thus, the temperature activates eukaryotic LDHs via the same conformational changes observed in the allosteric bacterial LDHs. Our investigation provides an extended molecular picture of eukaryotic LDH's conformational landscape that enriches the static view based on crystallographic studies alone.
منابع مشابه
Homotropic activation via the subunit interaction and allosteric symmetry revealed on analysis of hybrid enzymes of L-lactate dehydrogenase.
L-Lactate dehydrogenase from Bifidobacterium longum shows homotropic activation by pyruvate as well as heterotropic activation by fructose 1,6-bisphosphate. Hybrid enzymes were produced from the wild-type subunit and a mutant subunit, whose substrate specificity was altered to that of malate dehydrogenase, and separated to analyze the substrate-induced homotropic activation mechanism. Oxamate, ...
متن کاملVARIATIONS BY EPINEPHRINE OF HEPATIC AND SERUM AMINOTRANSFERASES AND LACTATE DEHYDROGENASE IN THE RAT
Incubation of rat hepatocytes with epinephrine inhibited alanine aminotransferase (ALT) (80%) and aspartate aminotransferase (AST) (53%) activities with no effect on lactate dehydrogenase (LDH) activity. Injection of epinephrine caused a progressive increase with time in hepatic LDH activity, being 52% at 24 h. Preinjection with propranolol eliminated the hormone effect and caused further ...
متن کاملAn absolute requirement of fructose 1,6-bisphosphate for the Lactobacillus casei L-lactate dehydrogenase activity induced by a single amino acid substitution.
Lactobacillus casei allosteric L-lactate dehydrogenase (L-LDH) absolutely requires fructose 1,6-bisphosphate [Fru(1,6)P2] for its catalytic activity under neutral conditions, but exhibits marked catalytic activity in the absence of Fru(1,6)P(2) under acidic conditions through the homotropic activation effect of substrate pyruvate. In this enzyme, a single amino acid replacement, i.e. that of Hi...
متن کاملInsights into allosteric control of vinculin function from its large scale conformational dynamics.
Vinculin is an important constituent of both cell-cell and cell-matrix junctions, where it plays crucial roles in the regulation of cell adhesion and migration. When activated, it mediates the linkage between cadherins (cell-cell) or integrins (cell-matrix) and the actin cytoskeleton through interactions with various proteins. The activation of vinculin requires structural conversions from an a...
متن کاملThe levels of Serum Alkaline Phosphatase and Lactate Dehydrogenase in Hodgkin Lymphoma
Background: Hodgkin’s disease (HD) is a neoplastic disease originating in lymphoid tissue, which spreads to lymphoid structures and ultimately nonlymphoid tissues. Lactate Dehydrogenase and Alkaline Phosphatase are increased in blood following membrane cell damage. The aim of this study was to compare Lactate Dehydrogenase and Alkaline Phosphatase levels in children in different stages of Hodg...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 7 شماره
صفحات -
تاریخ انتشار 2017