Correlation of co-ordinated amino acid changes at the two-domain interface of cysteine proteases with protein stability.
The engineering of a protein containing an alternative local residue packing for a set of side-chains has proven to be a major challenge because compositional, volumetric and steric constraints must be respected. Homologous proteins should provide examples of alternative groups of residues leading to a similar functional result. The functional significance of a pair of co-ordinated changes that are observed in the cysteine proteases family has been investigated by comparing the effect of individual or double changes on secretion, stability and activity of papain. The two changes are not independent. Detrimental effects of single mutations at one of the two positions can be partly suppressed by the co-ordinated mutation that reproduces naturally occurring contacts, indicating that these changes are concerted. Single mutations at the other position produce milder effects, suggesting a pathway for evolution.
Vernet
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Biotechnology Research Institute, National Research Council of Canada, Montréal, Québec.
Tessier
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Khouri
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Altschuh
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D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001483:Base Sequence; D002460:Cell Line; D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000378:metabolism; D004247:DNA; D004795:Enzyme Stability; D006358:Hot Temperature; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010206:Papain / Q000737:chemistry; D015202:Protein Engineering; D011498:Protein Precursors / Q000378:metabolism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D000596:Amino Acids; D011498:Protein Precursors; D004247:DNA; D003546:Cysteine Endopeptidases; D010206:Papain