Temperature-induced conformational changes in prosomatostatin-II: implications for processing
| Autor: | Xue Jun Tang, Steven C. Almo, Joydeep Mitra, Dennis Shields |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Protein Folding
Protein Conformation Dimer Molecular Sequence Data Prohormone Hypothalamus medicine.disease_cause Peptide Mapping Biochemistry Protein Structure Secondary law.invention Islets of Langerhans chemistry.chemical_compound law Escherichia coli medicine Trypsin Amino Acid Sequence Cloning Molecular Protein Precursors Protein precursor Molecular Biology Protein secondary structure Chromatography High Pressure Liquid Chemistry Circular Dichroism Monobasic acid Temperature Cell Biology Recombinant Proteins Protein Structure Tertiary Somatostatin Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization Recombinant DNA Biophysics Thermodynamics Dimerization Protein Processing Post-Translational Research Article medicine.drug |
| Zdroj: | Biochemical Journal. 334:275-282 |
| ISSN: | 1470-8728 0264-6021 |
| Popis: | Somatostatin (SRIF) is a 14-residue peptide hormone synthesized in the hypothalamus and pancreatic islets. SRIF-14 and an N-terminally extended form, SRIF-28, are generated by the proteolytic processing of an approx. 102-residue precursor prosomatostatin (proSRIF) at a single set of paired basic residues (Arg-Lys) and at a monobasic (Arg) site respectively. Previous work in our laboratory demonstrated that the propeptide of SRIF mediates intracellular sorting; we suggested that this information resides in the prohormone structure. To identify putative sorting domains we have investigated structural features of recombinant anglerfish proSRIF-II purified from Escherichia coli. Two species of proSRIF-II were obtained: a monomeric form and a disulphide-linked dimer. CD analyses revealed that monomeric proSRIF-II lacks appreciable periodic secondary structure; however, on slow heating (2 degrees C/min) and cooling, it assumed a predominantly alpha-helical conformation. When subjected to a second heating-and-cooling cycle, the alpha-helical conformation was maintained. In contrast, the dimeric form of proSRIF-II was predominantly alpha-helical and its helicity did not increase in response to heating and recooling. Our results suggest that proSRIF-II might exist in several different folding intermediate states. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|