Inclusion body formation and protein stability in sequence variants of interleukin-1 beta.


Inclusion body formation during recombinant protein expression in bacteria is of both fundamental interest and practical importance. To elucidate molecular mechanisms of this process, we are examining the in vitro folding and stability properties of a series of human interleukin-1 beta (IL-1 beta) sequence variants which exhibit widely differing tendencies to form inclusion bodies. Of 67 variants surveyed, nine, including wild type, were purified and their in vitro stability properties determined. One of these, a high inclusion body mutant, exhibited very low solubility in native buffer after purification and was not pursued further. For the other eight sequence variants, no strong correlations were observed between extent of inclusion body formation and either thermodynamic or thermal stability. In particular, a Lys97-->Val mutation produces substantially more IL-1 beta in inclusion bodies than the wild type (61 versus 8%) despite generating a protein more thermodynamically stable than wild type. Furthermore, the Lys97-->Val mutant forms substantial levels of inclusion bodies at 32 degrees C but requires incubation at temperatures greater than 48 degrees C for thermally induced aggregation in vitro. This and other data suggest that the tendency of at least some IL-1 beta variants to form inclusion bodies is most likely related to the stability or solubility of folding intermediates rather than native states. Implications of the structural locations of these mutations are also discussed. Study holds ProTherm entries: 17, 18, 19, 20, 21, 22, 23, 24 Extra Details: additive : EDTA(2 mM),dG and ddG were measured in the presence of 1.35M GdnHCl human interleukin-1 beta; protein stability; thermal stability;,inclusion body formation; folding intermediate

Submission Details

ID: 9NkveP3j3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:14 p.m.

Version: 1

Publication Details
Chrunyk BA;Evans J;Lillquist J;Young P;Wetzel R,J. Biol. Chem. (1993) Inclusion body formation and protein stability in sequence variants of interleukin-1 beta. PMID:8394358
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 Interleukin-1 beta P01584 IL1B_HUMAN
96.1 Interleukin-1 beta P48090 IL1B_MACMU
95.4 Interleukin-1 beta P51493 IL1B_MACNE
95.4 Interleukin-1 beta P79182 IL1B_MACFA
94.8 Interleukin-1 beta P46648 IL1B_CERAT