Effects of Protectants on the Activity of Wheat Mitochondria

Abstract

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.

Profiling subcellular localization of nuclear-encoded mitochondrial gene products in zebrafish

“…It actually neutralizes the negative action of fatty acids activated by phospholipases during cell disruption, which inhibits proper function of mitochondria by uncoupling oxidative phosphorylation (OXPHOS) ( Di Paola & Lorusso, 2006 ; Ngo et al, 2021 ). At high concentration, BSA may protect mitochondrial proteins from degradation, serving as an alternative substrate for proteases released upon cell breakage ( Goldstein et al, 1981 ). The comparison between the IB-M isolated and the EDTA-stripped MB fractions (isolated with IB-E containing BSA), once again proved the presence of intact mitochondria and enrichment of cytosolic ribosomal subunits in the IB-M isolated fraction ( Fig 1C ).…”