Related Experiment Video
Updated: Aug 8, 2026

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c
Published on: June 29, 2011
Critical segment of apocytochrome c for its insertion into membrane
Xiaoping Wang1, Xuehai Han, Fuyu Yang
1National Laboratory of Biomacromolecules, Institute of Biophysics, The Chinese Academy of Sciences, Beijing, China.
Abstract:
Apocytochrome c has a potent ability to insert spontaneously into membrane. To identify which sequences were critical for this insertion activity, a series of peptides N19, C8, C15 and C21, corresponding to sequences 1-19, 81-88, 74-88 and 68-88 of apocytochrome c, respectively, were synthesized and purified. Insertion ability into phospholipid monolayer, intrinsic fluorescence emission spectra, and the accessibility of peptide C21 to fluorescence quenchers: KI, acrylamide and HB showed that only segment 68-88 could insert into membrane, while other segments did not. CD spectra demonstrated that its interaction with liposomes containing negatively charged phospholipid could induce a partial alpha-helical conformation in peptide C21. It is interesting to note that a cooperation exists between segment 68-88 and 1-19 in the insertion of apocytochrome c and consequently translocation across membrane.
More Related Videos
Related Concept Videos
Mitochondrial Precursor Proteins
Most of the mitochondrial precursors...
Protein Transport into the Inner Mitochondrial Membrane
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Protein Transport to the Outer Chloroplast Membrane
Two models describe the mechanism of precursor recognition and entry across the outer membrane through the TOC complex. Model 1 suggests the newly synthesized precursor binds to the TOC receptor 159 and forms a complex.
Insertion of Single-pass Transmembrane Proteins in the RER
Integral transmembrane proteins possess transmembrane and extra membrane domains. The transmembrane domains are primarily made of 20-25 hydrophobic amino acids arranged in a helical secondary confirmation. These...
Insertion of Multi-pass Transmembrane Proteins in the RER
The multipass transmembrane proteins are the type IV integral membrane proteins with multiple topogenic sequences determining their spatial arrangement in the ER membrane. Nearly all multipass proteins lack a cleavable signal sequence and use...
Protein Transport to the Inner Chloroplast Membrane

