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Updated: Aug 18, 2026

Measurement of Protein Import Capacity of Skeletal Muscle Mitochondria
Published on: January 7, 2022
The dimensions of the protein import channels in the outer and inner mitochondrial membranes
1Department of Biochemistry, Northwestern University, 2153 Sheridan Road, Evanston, IL 60208-3500, USA.
Abstract:
Most mitochondrial proteins are imported into mitochondria through transmembrane channels composed largely, and perhaps exclusively, of proteins. We have determined the effective internal diameter of the protein import channel in the mitochondrial outer membrane to be between 20 A and 26 A during translocation. The diameter of the import channel in the inner membrane is smaller than the diameter of the outer membrane import channel. These results were obtained by measuring the effect of rigid steric bulk introduced into precursor proteins on import.
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