Kinetic analysis of demetalation of bacteriochlorophyll c and e homologs purified from green sulfur photosynthetic bacteria.
Substituent-dependent demetalation kinetics of natural bacteriochlorophyll (BChl) c and e homologs purified from two green sulfur photosynthetic bacteria was first studied. Separated BChl e homologs, which possessed a formyl group at the 7-position of their chlorin macrocycles, exhibited a significantly slow removal of central magnesium to free-base bacteriopheophytins in acidic aqueous acetone compared with the corresponding BChl c homologs, which possessed a methyl group at the 7-position. Additional methyl groups at the 8(2)-position of both BChl c and e molecules had little effect on the demetalation kinetics.
Saga
Yoshitaka
Y
Department of Chemistry, Faculty of Science and Engineering, Kinki University, Higashi-Osaka, Osaka 577-8502, Japan. saga@chem.kindai.ac.jp <saga@chem.kindai.ac.jp>
Hirai
Yuki
Y
Tamiaki
Hitoshi
H
D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D001429:Bacteriochlorophylls / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D019414:Chlorobi; D007700:Kinetics; D008274:Magnesium / Q000378:metabolism*; D008954:Models, Biological; D011489:Protein Denaturation; D017386:Sequence Homology, Amino Acid; D013057:Spectrum Analysis
D001426:Bacterial Proteins; D001429:Bacteriochlorophylls; C120930:bacteriochlorophyll e; C002084:bacteriochlorophyll c; D008274:Magnesium