caa a22 4500 475743857 CHVBK 20180406123507.0 cr unu---uuuuu 170329e20000101xx s 000 0 eng 10.1023/A:1007027623966 doi (NATIONALLICENCE)springer-10.1023/A:1007027623966 On the Thermal Unfolding Character of Globular Proteins [Elektronische Daten] [R. Muthusamy, M. Gromiha, P. Ponnuswamy] A theoretical model is presented to study the stepwise thermal unfolding of globular proteins using the stabilizing/destabilizing characters of amino acid residues in protein crystals. A multiple regression relation connecting the melting temperature and the amounts of stabilizing and destabilizing groups of residues in a protein, when used for the thermal behavior of peptide segments, provides reliable results on the stepwise unfolding nature of the protein. In ribonuclease A, the shell residues 16-22 are predicted to unfold earlier in the temperature range 30-45°C; the β-sheet structures undergo thermal denaturation as a single cooperative unit and there is evidence indicating the segment 106-118 as a nucleation site. In ribonuclease S, the S-peptide unfolds earlier than S-protein. The predicted average and the range of melting temperatures, and the folding pathways of a set of globular proteins, agree very well with the experimental results. The results obtained in the present study indicate that (i) most of the nucleation parts possess high relative thermal stability, (ii) the unfolded state retains some residual structure, and (iii) some segments undergo gradual and overlapping thermal denaturation. Plenum Publishing Corporation, 2000 Folding pathway nationallicence nucleation site nationallicence thermal stability nationallicence amino acid residue nationallicence melting temperature nationallicence Muthusamy R. Department of Physics, Bharathidasan University, Tiruchirapalli, 620 024, Tamil Nadu, India aut Gromiha M. RIKEN Life Science Center, 3-1-1 Koyadai, Tsukuba, 305-0074, Ibaraki, Japan aut Ponnuswamy P. Department of Physics, Bharathidasan University, Tiruchirapalli, 620 024, Tamil Nadu, India aut Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/1(2000-01-01), 1-8 0277-8033 19:1<1 2000 19 10930 https://doi.org/10.1023/A:1007027623966 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1007027623966 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Muthusamy R. Department of Physics, Bharathidasan University, Tiruchirapalli, 620 024, Tamil Nadu, India aut NATIONALLICENCE 700 1- Gromiha M. RIKEN Life Science Center, 3-1-1 Koyadai, Tsukuba, 305-0074, Ibaraki, Japan aut NATIONALLICENCE 700 1- Ponnuswamy P. Department of Physics, Bharathidasan University, Tiruchirapalli, 620 024, Tamil Nadu, India aut NATIONALLICENCE 773 0- Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/1(2000-01-01), 1-8 0277-8033 19:1<1 2000 19 10930 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer