Sjöstrand F S, Allen B S, Beyersdorf F, Buckberg G
Department of Biology, University of California, Los Angeles 90024-1606.
J Ultrastruct Mol Struct Res. 1988 Apr;99(1):1-17.
An experimentally imposed 6-hr local ischemia in the anterior wall of the left ventricle in dog hearts leads to a structural modification of the mitochondria in the posterior wall with the cristae revealing a zig-zag pattern when viewed in cross sections. This pattern was found to reveal a change in the distribution of crista mass with an increase of mass at circumscribed regions in each crista membrane and a reduction of mass from the surrounding region in each crista membrane. The accumulation of mass contributed to the elevations that caused the zig-zag pattern. These elevations were distributed according to a tetragonal pattern with a periodicity of 850 A. The tetragonal pattern contributed by one crista membrane was translocated halfway along the diagonals of the tetrameric pattern of the other crista membrane within each crista. The change in mass distribution reveals differences in the strength of bonds that account for binding of the proteins to the cristae with strong bonds in the elevated regions, while enzymes less firmly bound are located in the surrounding region. The respiratory chain enzymes will then be located in the elevated regions and the soluble enzymes including the tricarboxylic acid cycle enzymes will be located in the surrounding region. The tissue in the posterior wall was functionally impaired and normal function was restored when substrate for oxidative phosphorylation was added to the blood perfusing the tissue. It is concluded that the functional impairment is a consequence of a partial breakdown of the structural organization of the tricarboxylic acid cycle enzymes. The discovery of a long-range structural order involving the entire cristae reveals that the enzymes of the multienzyme systems as well as those systems in the cristae are structurally highly organized and it excludes that the enzymes are randomly mixed and highly mobile.
在犬心左心室前壁进行实验性施加的6小时局部缺血，会导致后壁线粒体结构改变，其嵴在横切面上呈现出锯齿状。发现这种模式揭示了嵴质量分布的变化，即每个嵴膜的限定区域质量增加，而每个嵴膜周围区域质量减少。质量的积累导致了形成锯齿状模式的隆起。这些隆起呈四方模式分布，周期为850埃。一个嵴膜形成的四方模式在每个嵴内沿着另一个嵴膜四聚体模式的对角线平移了一半距离。质量分布的变化揭示了蛋白质与嵴结合的键强度差异，隆起区域的键强，而结合较不牢固的酶位于周围区域。呼吸链酶将位于隆起区域，而包括三羧酸循环酶在内的可溶性酶将位于周围区域。后壁组织功能受损，当向灌注该组织的血液中添加氧化磷酸化底物时，正常功能得以恢复。结论是，功能受损是三羧酸循环酶结构组织部分破坏的结果。涉及整个嵴的远程结构顺序的发现表明，多酶系统的酶以及嵴中的那些系统在结构上高度有序，这排除了酶是随机混合且高度可移动的可能性。
