Effects of protectants on the activity of wheat mitochondria.
A mitochondrial fraction was isolated from durum wheat seedlings via differential centrifugation using three different tissue grinding buffers. One buffer contained bovine serum albumin (BSA), a protein proven effective in protecting mitochondria from damage during isolation. The other two buffers contained either polyethyleneglycol of M.W. 20,000D (PEG-20), a phenolic binding compound or PEG-20 plus XAD-2, a non-ionic adsorbent material. Organelles isolated with the BSA exhibited an average ADP/O ratio of 2.3 and an average respiratory control ratio of 5.1, substantially higher than those obtained with the other media. Addition of the XAD-2 to a buffer containing PEG-20 resulted in an increase in the respiratory control ratio to an average value of 3.7 vs 2.7 for organelles isolated with PEG-20 alone without causing a concomitant rise in the ADP/O ratio which remained an average of 1.9. Protein values for the mitochondrial fraction isolated with BSA ranged from 2.5 to 3 times greater than those obtained from the PEG-20 preparations. This difference in organelle protein is discussed in relation to the accurate measurement of mitochondrial respiration.
D002458:Cell Fractionation / Q000379:methods; D002499:Centrifugation, Density Gradient / Q000379:methods; D007475:Ion Exchange Resins / Q000494:pharmacology; D008854:Microscopy, Electron; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D010101:Oxygen Consumption / Q000187:drug effects; D010944:Plants / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000494:pharmacology*; D011137:Polystyrenes / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000494:pharmacology*; D014908:Triticum / Q000378:metabolism
D007475:Ion Exchange Resins; D011137:Polystyrenes; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols; C003771:Amberlite XAD-2 resin