Amy C M, Rebhun L I
J Cell Physiol. 1979 Jul;100(1):187-98. doi: 10.1002/jcp.1041000119.
Cell division in fertilized sea urchin eggs was reversibly inhibited when the ketoaldehyde phenyl glyoxal (PG) at a concentration of 0.1 mM was added to eggs for ten minutes prior to the formation of the mitotic spindle. We investigated whether inhibition of mitosis was due to PG binding to the cell surface (as previously suggested by Stein and Berestecky, '74) or to some intracellular effect. When 14C-PG was added to eggs, label was readily taken up into the egg cytoplasm; very little label was associated with the egg surface. In the cytoplasm PG combined with equimolar amounts of reduced glutathione (GSH), decreasing the levels of cellular GSH to less than 15% of normal and accounting for at least 50% of the PG taken up by eggs. The concentrations of oxidized and protein-bound glutathione were unaffected by PG treatment. We showed that glyoxalase enzymes were present in sea urchin eggs and were capable of metabolizing the PG-GSH complex, thereby restoring GSH to normal levels after PG was removed from the sea water. Though some other effect of PG cannot be ruled out, the major fate of PG in eggs was to combine with GSH, and the transient decrease in GSH which resulted could lead to inhibition of mitosis. While other reports (Nath and Rebhun, '76; Oliver et al., '76) have shown that reagents which oxidize GSH disrupt microtubule-related events, our results showed that such inhibition could be caused by decreased GSH levels alone.
当在有丝分裂纺锤体形成前10分钟，向海胆受精卵中加入浓度为0.1 mM的酮醛苯乙二醛（PG）时，受精卵的细胞分裂受到可逆性抑制。我们研究了有丝分裂的抑制是由于PG与细胞表面结合（如Stein和Berestecky在1974年之前所提出的）还是由于某些细胞内效应。当向卵中加入14C-PG时，标记物很容易被吸收到卵细胞质中；与卵表面结合的标记物很少。在细胞质中，PG与等摩尔量的还原型谷胱甘肽（GSH）结合，使细胞内GSH水平降至正常水平的15%以下，且占卵摄取的PG的至少50%。氧化型和与蛋白质结合的谷胱甘肽的浓度不受PG处理的影响。我们发现海胆卵中存在乙二醛酶，并且能够代谢PG-GSH复合物，从而在从海水中去除PG后将GSH恢复到正常水平。尽管不能排除PG的其他一些作用，但PG在卵中的主要命运是与GSH结合，由此导致的GSH短暂减少可能会导致有丝分裂的抑制。虽然其他报告（Nath和Rebhun，1976年；Oliver等人，1976年）表明氧化GSH的试剂会破坏与微管相关的事件，但我们的结果表明，这种抑制可能仅由GSH水平降低引起。
