|Title||Measurements of DNA lengths remaining in a viral capsid after osmotically suppressed partial ejection|
|Publication Type||Journal Article|
|Year of Publication||2005|
|Authors||A. Evilevitch, J. W. Gober, M. Phillips, C. M. Knobler and W. M. Gelbart|
|Journal Title||BIOPHYSICAL JOURNAL|
|Type of Article||Journal Article|
|Keywords||BACTERIOPHAGE-LAMBDA, EXPRESSION, FORCES, PHAGE, SEDIMENTATION|
The effect of external osmotic pressure on the extent of DNA ejection from bacteriophage-lambda was recently investigated (Evilevitch et al., 2003). The total length of DNA ejected was measured via the 260-nm absorption by free nucleotides, after opening of the capsids in the presence of varying amounts of polyethylene glycol 8000 and DNase I. As a function of osmolyte concentration, this absorption was shown to decrease progressively, ultimately vanishing completely for a sufficiently high external osmotic pressure. In this work we report the results of both sedimentation and gel analysis of the length of DNA remaining inside the capsids, as a function of osmolyte concentration. It is confirmed in this way that the progressive inhibition of DNA ejection corresponds to partial ejection from all of the capsids.