Protein turnover membranes affecting

Use of a high field to activate a membrane enzyme was first reported by Witt et al. (25) in 1976. They used dc pulses of approximately 1 kV/cm and of 1-ms duration to induce ATP synthesis by the chloroplast ATPase. Following this initial work, there have been many reports on 1-kV/ cm dc field-induced ATP synthesis in different ATP synthetic systems (see the literature cited in references 13 and 14). The main conclusion from these studies is that an applied field-induced transmembrane potential can facilitate ATP release from the enzyme whether a PEF can affect enzyme turnover is not clear. Because 1-kV/ cm dc fields also cause severe Joule heating of a sample suspension, thermal effects cannot be easily avoided except when very short electric pulses (microseconds) are used. Thus, the method has limited utility for electroactivation experiments. The PEF method is, however, quite popular for the study of electroporation and electrofusion of cell membranes (see the chapter by J. Weaver in this volume), electroinsertion of membrane proteins (26), and electrotransfection of cells (27). 

However, not just CPT-I, but all CPT enzymes that use c>4oriasmic substrates are regulated by malonyl-CoA and inhibited by TDGA and etomoxir. Thus, these drugs will also interfere with peroxisomal oxidation and influence microsomal acyl-CoA utilizing pathways such as lipid s nithesis and lipid modification of proteins for export. In view of recent indications that non-mitochondrial acyl-CoA pools may influence membrane turnover, this may not be desirable, so inhibitors specific to CPT-I would be better. We have studied the kinetics and inhibition of two of the CPT family of enzymes as the first step towards finding differences that could be exploited to inhibit -oxidation without affecting peripheral function. 

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