Mass spectrometric identification of various molecular forms of dynorphin in bovine adrenal medulla

Deliberate miscompartmentalization of liver outer mitochondrial membrane (OMM) proteins and liver mitochondrial proteins has been achieved by polyethylene-glycol mediated OMM vesicle-hepatocyte or mitochondrial-hepatocyte fusion. Reductively methylated OMM and mitochondrial proteins (³H) are destroyed at rates remarkably similar to those for OMM ($\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, 60–70 h) or mitochondrial proteins ($\text{t}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, 84–104 h) in liver $\text{in vivo}$ when studied over 4–5 days in hepatocyte monolayers cultured in conditions giving stabilized endogenous protein catabolic rates mimicking endogenous $\text{in vivo}$ rates. Destruction of transplanted OMM proteins is partially sensitive to chloroquine, supporting some lysosomally mediated autophagic destruction of long-lived transplanted OMM proteins in hepatocyte monolayers.