Fic蛋白家族的研究进展

过去的研究发现了一个具有相同保守结构域的Fic(filamentation induced by cAMP)蛋白家族。虽然在原核生物中发现超过3 000种以上含有Fic结构域的不同蛋白质,但到目前为止,在包括人在内的真核生物中仅发现一种Fic蛋白。Fic结构域主要通过含有磷酸基团的化合物在转录中起作用,目前被人类关注的功能是单酰磷酸化(AMPylation, AMP化),一种类似磷酸化的蛋白质调控机制,是以ATP为底物将一磷酸腺苷(AMP)特异地转移至靶标氨基酸残基。该机制主要在细菌侵袭宿主、侵袭后增殖、致病的过程中发挥作用。真核细胞中的单磷酸腺苷化可以调控内质网的稳定性。本文主要对Fic蛋白的特征性结构和作用以及几种主要的Fic蛋白的结构、作用和研究方法进行综述。     

Bactericidal activity of ethanol against glucose nonfermentative Gram-negative bacilli

The bactericidal effect of ethanol on glucose nonfermentative Gram-negative bacilli (nonfermentative bacilli) and other species of micro-organisms was studied with emphasis on the former. At 20 degrees C, 10 to 20% v/v ethanol took 1 h or more to kill thirteen strains of nonfermentative bacilli while 40 to 99.5% concentrations produced a bactericidal effect within 1 min of exposure. Eleven strains of glucose fermentative organisms showed a similar tendency to that noted with nonfermentative bacilli, except that S. aureus was a little resistant to 99.5% ethanol. Using several strains of nonfermentative bacilli, the effects of temperature and equine serum on the bactericidal action of ethanol were determined. The bactericidal action of ethanol increased with rising of temperature (10-30 degrees C), and it was sufficient even at 10 degrees C provided that the concentration of ethanol was over 50%. The equine serum produced little effect on the bactericidal action of ethanol.