Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:3.4.21.9 (
enterokinase
)
675
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
As a step toward studying membrane fusion with a simplified molecule, the ectodomain, residues 1-185, of the membrane-anchored subunit
HA2
of the influenza virus haemagglutinin (HA) was solubilized by adding the very polar FLAG octapeptide (Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys) to the N-terminal
HA2
fusion peptide. The resulting chimeric protein, F185, when expressed in bacteria, folded spontaneously into a soluble trimer, with a high alpha-helical content and a high melting temperature, structural characteristics of the low-pH-induced conformation of
HA2
. Removal of the FLAG octapeptide by proteolysis with
enterokinase
converted the soluble molecule to one that aggregated, bound nonionic detergent, and bound to lipid vesicles, properties of the low-pH-induced conformation of HA. Thermolysin treatment of the aggregated protein removed the nonpolar fusion peptide, regenerating soluble trimers of
HA2
(residues 24-185), which is analogous to thermolysin treatment of HA in the low-pH-induced conformation. Thermolysin treatment also dissociates F185 from the detergent-protein complex by removing the fusion peptide. These results suggest that highly polar peptides can be fused to the membrane-binding regions of membrane proteins to increase their solubility. They also indicate that ectodomains of
HA2
made in bacteria have membrane-binding properties similar to those of the same ectodomain generated by low-pH treatment of HA isolated from virus.
...
PMID:A polar octapeptide fused to the N-terminal fusion peptide solubilizes the influenza virus HA2 subunit ectodomain. 975 51
