Effect of temperature on the circular dichroism spectra of beta 2-microglobulins.
When the temperature was lowered from 25 to 5 degrees C dramatic changes were observed in the near-ultraviolet circular dichroism spectra of bovine and caprine but not human beta 2-microglobulin. Comparison of the protein sequences suggests that the conformational change occurs in the amino-terminal 24 residues and that a tyrosine residue located on a potential beta-turn acts as a reporter group. Because delta H degrees is small (-22 kcal X mol-1), such conformational changes, possibly not readily observed, may occur at low temperatures in other proteins having potential beta-turns in otherwise aperiodic regions of sequence.
D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D006041:Goats; D006801:Humans; D011487:Protein Conformation; D013045:Species Specificity; D013696:Temperature; D001613:beta 2-Microglobulin / Q000032:analysis*
D001613:beta 2-Microglobulin