Fatty acid binding and conformational stability of mutants of human muscle fatty acid-binding protein.


Human muscle fatty acid-binding protein (M-FABP) is a 15 kDa cytosolic protein which may be involved in fatty acid transfer and modulation of non-esterified fatty acid concentration in heart, skeletal muscle, kidney and many other tissues. Crystallographic studies have suggested the importance of the amino acids Thr-40, Arg-106, Arg-126 and Tyr-128 for the hydrogen bonding network of the fatty acid carboxylate group. Two phenylalanines at 16 and 57 are positioned to interact with the acyl chain of the fatty acid. We prepared 13 mutant proteins by site-directed mutagenesis and tested them for fatty acid binding and stability. Substitution of amino acids Phe-16, Arg-106 or Arg-126 created proteins which showed a large decrease in or complete loss of oleic acid binding. Substitution of Phe-57 by Ser or Val and of Tyr-128 by Phe had no great effect. The stability of the mutant proteins was tested by denaturation studies on the basis of fatty acid binding or tryptophan fluorescence and compared with that of the wild-type M-FABP. There was no direct relationship between fatty acid-binding activity and stability. Less stable mutants (F57S and Y128F) did not show a marked change in fatty acid-binding activity. Substitution of Arg-126 by Gln or Arg-106 by Thr eliminated binding activity, but the former mutant protein showed wild-type stability, in contrast to the latter. The results are in agreement with crystallographic data. Study holds ProTherm entries: 7258, 7259, 7260, 7261, 7262, 7263, 7264, 7265, 7266, 7267, 7268, 7269, 7270 Extra Details:

Submission Details

ID: RvYhZxg64

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:33 p.m.

Version: 1

Publication Details
Prinsen CF;Veerkamp JH,Biochem. J. (1996) Fatty acid binding and conformational stability of mutants of human muscle fatty acid-binding protein. PMID:8660291
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Fatty acid-binding protein, heart P05413 FABPH_HUMAN
90.2 Fatty acid-binding protein, heart O02772 FABPH_PIG
91.0 Fatty acid-binding protein, heart Q99P61 FABPH_ICTTR
90.1 Fatty acid-binding protein, heart P07483 FABPH_RAT