Destabilizing loop swaps in the CDRs of an immunoglobulin VL domain.
It is generally believed that loop regions in globular proteins, and particularly hypervariable loops in immunoglobulins, can accommodate a wide variety of sequence changes without jeopardizing protein structure or stability. We show here, however, that novel sequences introduced within complementarity determining regions (CDRs) 1 and 3 of the immunoglobulin variable domain REI VL can significantly diminish the stability of the native state of this protein. Besides their implications for the general role of loops in the stability of globular proteins, these results suggest previously unrecognized stability constraints on the variability of CDRs that may impact efforts to engineer new and improved activities into antibodies.
Macromolecular Sciences Department, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406, USA.
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D000595:Amino Acid Sequence; D001792:Blood Platelets; D002942:Circular Dichroism; D019791:Guanidine; D006146:Guanidines; D006801:Humans; D006860:Hydrogen Bonding; D007147:Immunoglobulin Light Chains / Q000737:chemistry*; D007135:Immunoglobulin Variable Region / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009842:Oligopeptides; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000737:chemistry / Q000302:isolation & purification; D011489:Protein Denaturation; D017510:Protein Folding; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship; D013816:Thermodynamics
D006146:Guanidines; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D009842:Oligopeptides; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011994:Recombinant Proteins; C047981:arginyl-glycyl-aspartic acid; D019791:Guanidine