Related Experiment Video
Updated: Aug 12, 2026

Identification of Post-translational Modifications of Plant Protein Complexes
Published on: February 22, 2014
Expression of recombinant pro-neuropeptide Y, proopiomelanocortin, and proenkephalin: relative processing by
M R Schiller1, A B Kohn, L M Mende-Muelller
1Department of Biochemistry, Uniformed Services University, Bethesda, MD, USA.
Abstract:
The preference of the 'prohormone thiol protease' (PTP), a candidate prohormone processing enzyme, for different peptide precursors was assessed in vitro with recombinant prohormones near estimated in vivo levels. Pro-neuropeptide Y (pro-NPY), proopiomelanocortin (POMC), and proenkephalin (PE) were expressed at high levels in E. coli. Purification of prohormones utilized a combination of DEAE-Sepharose, Mono Q, and preparative electrophoresis. PTP cleaved PE most readily, and also cleaved pro-NPY. The processing of POMC by PTP was minimal. These results demonstrate PTP's preference for certain prohormone substrates.
Related Concept Videos
Mitochondrial Precursor Proteins
Most of the mitochondrial precursors...
Translocation of Proteins into the Mitochondria
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Protein Import into the Peroxisomes
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
The Proteasome Structure
The proteasome is an...

