Tutorial 3

Tutorial 1: How to retrieve data in ProThermDB for a specific protein?

Tutorial 2: How to retrieve the mutations, which have ΔΔGH2O values of more than 2 kcal/mol?

Tutorial 3: How to get a list of single mutations, which are in α-helices and have ΔΔG values of more than 0 kcal/mol ?

Step 1: Go to “search options”, select the mutation type “single” and secondary structure “Helix” in the respective fields. Enter the minimum value as zero in ΔΔG field. You may provide the maximum value or ProThermDB will choose the maximum value automatically (highest value in the database).
Step 2: Choose the desired columns in display options.

1

1

Tutorial 4: How to download the ΔTm data for Alanine to Valine single mutations at pH 6 to 9, which are obtained from thermal denaturation experiments?



Glossary of terms


Terms
Explanations
No Entry number. This option can be used for getting data from a particular entry (Eg. 31243)
Protein Name Name of the protein
E_C_number Enzyme Commission number
PDB Protein Data Bank code for the native protein
STATE Number of transition states
Mutation Details about the mutation: residue in wild type, residue number and residue in mutant protein (e.g. G145R)
Sec str Secondary Structural Information for the mutation site (Helix, Strand, Turn and Coil; we obtain the data from PDB)
In search result : H = Helix, S = Strand, T = Turn, C = Coil.
Accessible Surface Area Accessible surface area (ASA) of the residue in wild type. Accessibility (%) is defined as the ASA of the residue at the mutation site (X) in its parent protein, computed with DSSP divided by the ASA of the residue in an extended tripeptide Ala-X-Ala conformation.The extended state ASA was calculated using ECEPP/2 algorithm with dihedral angles given by Oobatake and Ooi (Prog. Biophys. Mol. Biol. (1993) 59, 237-284) and the van der Waals radius of atoms from Ooi et al. (Proc. Natl. Acad. Sci. USA. (1987) 84, 3086-3090). The values are Ala-110.2; Asp-144.1; Cys-140.4; Glu-174.7; Phe-200.7; Gly-78.7; His-181.9; Ile-185.0; Lys-205.7; Leu-183.1; Met-200.1; Asn-146.4; Pro-141.9; Gln-178.6; Arg-229.0; Ser-117.2; Thr-138.7; Val-153.7; Trp-240.5; Tyr-213.7 (the units are in A**2). We classifed the residues with less than 20% accessibility as buried, between 20% and 50% as partially buried and more than 50% as exposed.
Measure The experiments performed to measure the thermodynamic parameters (Fluorescence spectroscopy, Circular Dichroism, Differential Scanning Calorimetry, Absorbance, NMR, etc.) Keywords: Fl, CD, DSC, Abs, NMR, others
Method Experimental method of denaturation (keywords: Thermal, Urea, GdnHCl etc.). (activity: 50% relative remaining activity of the enzyme after the heat treatment)
pH the pH value.
m Slope of ΔG on denaturant concentration (ΔG vs urea/GdnHCl; ΔG = ΔG(H2O) - m[Denaturant]).Unit is kcal/mol/M.
Cm Concentration of denaturant at which 50% of the protein is unfolded [M]
ΔTm Tm(mutant) - Tm(wild) [degree Celsius]. Positive and negative values of ΔTm indicate stabilizing and destabilizing mutations, respectively.
T In the case of denaturant denaturation methods, T is the temperature used in the experiment.[degree Celsius]
Tm Midpoint temperature of the thermal unfolding for thermal denaturation methods [degree Celsius]
ΔG (1) Free energy of unfolding at a certain concentration of denaturant in the case of denaturant denaturation methods
(2) Free energy of unfolding obtained for extrapolation temperature T using ΔCp in the case of thermal denaturation method [kcal/mol]
ΔΔG ΔG(mutant) - ΔG(wild) [kcal/mol] Free energy of unfolding obtained with Schellman equation (ΔΔG = dTm.ΔS) in the case of thermal denaturation method [kcal/mol]. Positive and negative values of ΔΔG indicate stabilizing and destabilizing mutations, respectively.​
ΔΔG_H2O ΔG_H2O(mutant) - ΔG_H2O(wild) [kcal/mol]. Positive and negative values of ΔΔGH2O indicate stabilizing and destabilizing mutations, respectively.
ΔH Enthalpy change of denaturation [kcal/mol]
ΔHvH van't Hoff enthalpy change of denaturation (enthalpy obtained from the temperature dependence of the denaturation equilibrium constant)
ΔCp Heat capacity change of denaturation [kcal/mol/K]
ΔG_H2O Free Energy of unfolding in water, determined by denaturant (urea; GdnHCl; GSSG/GSH; GdnSCN) denaturation of proteins and extrapolation of the data to zero concentration of denaturant [kcal/mol]
Reversibility Reversibility of denaturation. If the reversibility is mentioned in the paper, "Yes" (and % of reversibility if described) or "No" is listed, or otherwise this field is set to Unknown.
Key_words List of keywords used for the specific protein/article Multiple words can be entered with spaces.
Author Name of the authors.
Year Year of publication.
Reference Complete reference of the article with a link to NCBI database with PMID
Remarks Some specific comments
Source Source of the protein
Length Total number of Amino Acid residues in the protein
No of molecule Number of chains in protein
Buffer_name Name of the buffer used in the experiment
Buffer_conc Concentration of the buffer
Ion_name Name of the added ion
Ion_conc Concentration of the ion
ADDITIVES Details about the additives (e.g. glycerol)
Protein_conc Concentration of the protein when the experiment has been performed
RELATED_ENTRIES List of all the entries that contain other data reported in the same reference.