ISSN:
1573-4919
Keywords:
membrane fusion
;
permeability change
;
Sendai virus
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Summary A new assay for membrane fusion, using the fluorescent probe pyrene-sulphonyl-phosphatidyl ethanolamine, has been developed. Fusion between the envelope of Sendai virus and human erythrocytes or Lettre cells has a Q10 of ∼4 at 37° C, increasing to ∼7 at 7 ° C; there is no lag to onset of fusion. Viral neuraminidase has a Q10 of 2.3 between 37° C and 4° C. Its action limits the extent of fusion by causing the elution of virus; this effect is particularly marked at low temperature because of the difference in Q10 for fusion and neuraminidase. The temperature-dependence of the initiation of permeability changes following the removal of inhibitory amounts of Ca2+ is ∼2; thus membrane fusion is the principal temperature-sensitive step during the permeabilization of cells by Sendai virus. A recovery process, by which cells become insensitive to the removal of Ca2+ and which therefore limits the extent of permeabilization, has a Q10 of 7.4 between 37° C and 21° C. It is concluded that the lag to onset of permeability changes is not due to a lag in virus-cell membrane fusion, but to the gradual acquisition of a threshold level of membrane damage; the extent of permeabilization depends on the rate of fusion relative to the rates of neuraminidase and recovery.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00220784
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