پاورپوینت روش های بیوشیمی (pptx) 9 اسلاید

دسته بندی : پاورپوینت

نوع فایل : PowerPoint (.pptx) ( قابل ویرایش و آماده پرینت )

تعداد اسلاید: 9 اسلاید

قسمتی از متن PowerPoint (.pptx) :

روش های بیوشیمی زمستان 1395 جلسه دوم Previous section Cell disruption using physical or chemical methods in an appropriate buffer Clarification by centrifugation to pellet membranes Protein precipitation Removal of salts by dialysis, membrane filtration or size exclusion chromatography 2 3 Protein precipitation Rapid gentle scalable relatively inexpensive 4 Protein in solution 5 Ammonium sulfate Keep intact protein structure very soluble relatively inexpensive pure material is readily available Disrupts water structure around the protein molecule Allows hydrophobic regions to interact Protein precipitates out of solution In general, higher MW proteins precipitate out at lower concentrations of ammonium sulfate than lower MW proteins Therefore, differential ammonium sulfate precipitation provides a pre-purification step for proteins and is one of the classical methods used for protein purification 6 Ammonium sulfate precipitation 7 Isoelectric precipitation 8  other ways…  organic solvents decrease the dielectric constant of water, which in effect allows two proteins to come close together Non-ionic hydrophilic polymers such as dextrans and polyethylene glycols, are frequently used to precipitate proteins because they have low flammability and are less likely to denature biomaterials than isoelectric precipitation.  9  dialysis