The denaturation of the c-type cytochrome of the thermophilic bacterium Hydrogenobacter thermophilus cytochrome c-552 by heat and guanidine hydrochloride was studied by measuring the change in circular dichroic spectra. The melting temperature (T1/2) of cytochrome c-552 in the presence of 1.5 M guanidine hydrochloride was 34 degrees C higher than that of the c-type cytochrome of Pseudomonas aeruginosa cytochrome c-551. Hydrogenobacter cytochrome c-552 is a much more stable protein than cytochrome c-551 of the mesophilic bacterium P. aeruginosa, even though their amino acid sequences are 56% identical and they have numerous other similarities. However, notwithstanding these similarities between the sequences of the cytochromes c-552 and c-551 that were compared, it is very likely that these differences in stability could be due to some heretofore undefined differences in their spatial structures. It has been suggested that alpha-helix structure and electrostatic interaction could be the source of the stable spatial structure of cytochrome c-552. Study holds ProTherm entries: 3858, 3859, 3860, 3861, 3862, 3863, 3864, 3865 Extra Details: In the presence of 1.5M GdnHCl thermophilic hydrogen-oxidizing bacterium; spatial structures;,alpha-helix structure; electrostatic interaction
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:23 p.m.
|Number of data points||11|
|Proteins||Cytochrome c-552 ; Cytochrome c-551 ; Cytochrome c-552 ; Cytochrome c-551|
|Assays/Quantities/Protocols||Experimental Assay: dG_H2O ; Experimental Assay: Tm ; Experimental Assay: dHvH|
|Libraries||Mutations for sequence EDPEVLFKNKGCVACHAIDTKMVGPAYKDVAAKFAGQAGAEAELAQRIKNGSQGVWGPIPMPPNAVSDDEAQTLAKWVLSQK ; Mutations for sequence MKPYALLSLLATGTLLAQGAWAEDPEVLFKNKGCVACHAIDTKMVGPAYKDVAAKFAGQAGAEAELAQRIKNGSQGVWGPIPMPPNAVSDDEAQTLAKWVLSQK ; Mutations for sequence NEQLAKQKGCMACHDLKAKKVGPAYADVAKKYAGRKDAVDYLAGKIKKGGSGVWGSVPMPPQNVTDAEAKQLAQWILSIK|