Figure 1.
Stability curves of thermostable and mesostable proteins.
(a,b,c) Different strategies of thermal adaptation of hypothetic proteins. (d) Comparison between the stability curve of Tk-MGMT (PDB [47] code 1GMT) and its mesophilic counterpart Ec-AdaC (PDB code 1SFE) [32].)
Figure 2.
Flowchart of the protein stability curve prediction method.
Figure 3.
Predicted stability curves of the 45 proteins considered, which belong to 11 homologous families.
The PDB codes, the host organisms and their environmental temperatures of all the proteins are given in the following list: (a) 2vh7 (Homo sapiens, 37 ), 2bjd (Sulfolobus solfataricus, 80
), 1v3z (Pyrococcus horikoshii, 98
). (b) 1am7 (Bacteriophage lambda, 37
), 2lzm (Escherichia coli, 37
), 1lz1 (Homo sapiens, 37
), 1am7 (Gallus gallus, 41
). (c) 1aqh (Alteromonas haloplanktis, 26
), 1ppi (Sus scrofa, 39
), 1jae (Tenebrio molitor, 28
), 1smd (Homo sapiens, 37
). (d) 2fal (Aplysia limacina, 17
), 1ymb (Equus caballus, 38
), 1bvc (Physeter catodon, 35
). (e) 1blc (Staphylococcus aureus, 34
), 1ke4 (Escherichia coli, 37
), 4blm (Bacillus licheniformis, 43
), 1bmc (Bacillus cereus, 30
). (f) 1hml (Homo sapiens, 37
), 1hfz (Bos taurus, 38
), 1hmk(Capra hircus, 39
). (g) 1p3j (Bacillus subtilis, 37
), 3fb4 (Jeotgalibacillus marinus, 18
), 1s3g (Bacillus globisporus, 15
), 1aky (Saccharomyces cerevisiae, 28
), 1ank (Escherichia coli, 37
), 1zip (Bacillus stearothermophilus, 51
). (h) 1oa3 (Hypocrea schweinitzii, 40
), 1h8v (Thrichoderma reesei, 35
), 1oa4 (Streptomyces sp. 11ag8, 30
), 1olr (Humicola grisea, 50
), 1cec (Clostridium thermocellum, 60
). (i) 1csp (Bacillus subtilis,
), 1mjc (Escherichia coli, 37
), 1c9o (Bacillus caldolyticus, 70
). (j) 1bu7 (Bacillus megaterium, 30
), 1oxa (Saccharopolyspora erythraea, 31
), 1akd (Pseudomonas putida, 30
), 1n97 (Thermus thermophilus, 68
), 1f4t (Sulfolobus solfataricus, 78
). (k) 1rgg (Streptomyces aureofaciens, 28
), 9rnt (Aspergillus Oryzae, 49
), 1rnh (Escherichia coli, 37
), 1rbn (Bos taurus, 38
), 2ehg (Sulfolobus tokodaii, 80
).
Table 1.
Standard deviation () and linear correlation coefficient (
) between the experimental and predicted thermal and thermodynamic parameters.
Figure 4.
Comparison between: (a) the experimental and predicted melting temperatures (in °C), (b) the experimental and computed (in kcal/(mol °C)) and (c) the experimental and the predicted
(in kcal/mol), for the set of 45 proteins belonging to the 11 homologous families.
The straight lines correspond to the bisector of the first quadrant (y = x).