title: Remarkable thermal stability of doubly intramolecularly cross-linked hen lysozyme.
abstract: In order to examine how a protein can be effectively stabilized, two intramolecular cross-links, Glu35-Trp108 and Lys1-His15, which have few unfavorable interactions in the folded state, were simultaneously introduced into hen lysozyme. Both of the intramolecularly cross-linked lysozymes, 35-108 CL and 1-15 CL, containing cross-links Glu35-Trp108 and Lys1-His15, respectively, showed increases in thermal stability of 13.9 and 5.2 degrees C, respectively, over that of wild type, at pH 2.7. On the other hand, a doubly cross-linked lysozyme showed an increase in thermal stability of 20.8 degrees C over that of wild type, under identical conditions. Since the sum of the differences in denaturation temperature between wild type and each of the cross-linked lysozymes was nearly equal to that between wild type and the doubly cross-linked lysozyme, we suggest that the efficient stabilization of the lysozyme molecule was the direct result of the double intramolecular cross-links.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ueda
authors.forename: K
authors.initials: K
authors.lastname: Masumoto
authors.forename: R
authors.initials: R
authors.lastname: Ishibashi
authors.forename: T
authors.initials: T
authors.lastname: So
authors.forename: T
authors.initials: T
authors.lastname: Imoto
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites; D002152:Calorimetry, Differential Scanning; D002645:Chickens; D004529:Egg White; D004795:Enzyme Stability; D018698:Glutamic Acid; D006639:Histidine; D006358:Hot Temperature; D008239:Lysine; D009113:Muramidase / Q000737:chemistry*; D016297:Mutagenesis, Site-Directed; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry; D013816:Thermodynamics; D014364:Tryptophan
chemical_list: D011994:Recombinant Proteins; D018698:Glutamic Acid; D006639:Histidine; D014364:Tryptophan; D009113:Muramidase; D008239:Lysine