Premium
Structural transitions of porin, a transmembrane protein
Author(s) -
Schindler Melvin,
Rosenbusch Jürg P.
Publication year - 1984
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(84)81022-4
Subject(s) - porin , circular dichroism , chemistry , titration , membrane , transmembrane protein , bacterial outer membrane , membrane protein , protein structure , crystallography , polyacrylamide gel electrophoresis , biophysics , biochemistry , biology , inorganic chemistry , enzyme , receptor , escherichia coli , gene
Conformational transitions of porin were monitored using 3 independent criteria: (i) oligomeric state as observed by SDS‐polyacrylamide gel electrophoresis; (ii) spectroscopic titrations (ultraviolet and circular dichroism) and (iii) chemical modifications. Four pH‐dependent transitions were observed with half‐maximal changes occurring at pH values of 1.6, 3.5, 11.2 and 12.4. Two of these pH values differ significantly from intrinsic p K values of the constituent amino acids of this membrane protein. Since porin is very polar despite its location predominantly within the outer membranes, this may be due to ion pair formation in the hydrophobic environment of the membrane.