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Effects of freezing on membranes and proteins in LNCaP prostate tumor cells.
- Source :
-
Biochimica et biophysica acta [Biochim Biophys Acta] 2007 Mar; Vol. 1768 (3), pp. 728-36. Date of Electronic Publication: 2006 Dec 13. - Publication Year :
- 2007
-
Abstract
- Fourier transform infrared spectroscopy (FTIR) and cryomicroscopy were used to define the process of cellular injury during freezing in LNCaP prostate tumor cells, at the molecular level. Cell pellets were monitored during cooling at 2 degrees C/min while the ice nucleation temperature was varied between -3 and -10 degrees C. We show that the cells tend to dehydrate precipitously after nucleation unless intracellular ice formation occurs. The predicted incidence of intracellular ice formation rapidly increases at ice nucleation temperatures below -4 degrees C and cell survival exhibits an optimum at a nucleation temperature of -6 degrees C. The ice nucleation temperature was found to have a great effect on the membrane phase behavior of the cells. The onset of the liquid crystalline to gel phase transition coincided with the ice nucleation temperature. In addition, nucleation at -3 degrees C resulted in a much more co-operative phase transition and a concomitantly lower residual conformational disorder of the membranes in the frozen state compared to samples that nucleated at -10 degrees C. These observations were explained by the effect of the nucleation temperature on the extent of cellular dehydration and intracellular ice formation. Amide-III band analysis revealed that proteins are relatively stable during freezing and that heat-induced protein denaturation coincides with an abrupt decrease in alpha-helical structures and a concomitant increase in beta-sheet structures starting at an onset temperature of approximately 48 degrees C.
- Subjects :
- Biophysical Phenomena
Biophysics
Cell Line, Tumor
Cell Survival physiology
Freezing
Gels
Hot Temperature
Humans
Male
Phase Transition
Protein Conformation
Protein Denaturation
Protein Structure, Secondary
Spectroscopy, Fourier Transform Infrared
Cryopreservation
Neoplasm Proteins analysis
Prostatic Neoplasms pathology
Subjects
Details
- Language :
- English
- ISSN :
- 0006-3002
- Volume :
- 1768
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Biochimica et biophysica acta
- Publication Type :
- Academic Journal
- Accession number :
- 17239814
- Full Text :
- https://doi.org/10.1016/j.bbamem.2006.12.007