Hydrophobicity of amino acid residues: Differential scanning calorimetry and synthesis of the aromatic analogues of the polypentapeptide of elastin

Biopolymers ◽  
1992 ◽  
Vol 32 (9) ◽  
pp. 1251-1261 ◽  
Author(s):  
Chi-Hao Luan ◽  
Timothy M. Parker ◽  
D. Channe Gowda ◽  
Dan W. Urry
Keyword(s):  
Differential Scanning Calorimetry ◽  
Amino Acid ◽  
Amino Acid Residues ◽  
Scanning Calorimetry ◽  
Polypentapeptide Of Elastin

Thermophysical Study of Several α- and β-Amino Acid Derivatives by Differential Scanning Calorimetry (DSC)

2011 ◽  
Vol 56 (10) ◽  
pp. 3807-3812 ◽  
Author(s):  
María Victoria Roux ◽  
Rafael Notario ◽  
Marta Segura ◽  
Ramón Guzmán-Mejía ◽  
Eusebio Juaristi ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Amino Acid ◽  
Amino Acid Derivatives ◽  
Scanning Calorimetry

Influence of specific amino acid side-chains on the antimicrobial activity and structure of bovine lactoferrampin1This article is part of Special Issue entitled Lactoferrin and has undergone the Journal’s usual peer review process.

2012 ◽  
Vol 90 (3) ◽  
pp. 362-377 ◽  
Author(s):  
Evan F. Haney ◽  
Kamran Nazmi ◽  
Jan G.M. Bolscher ◽  
Hans J. Vogel
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Peer Review Process ◽  
Titration Calorimetry ◽  
Resonance Spectroscopy ◽  
Bovine Lactoferrin ◽  
Amino Acid Residues ◽  
Scanning Calorimetry ◽  
Specific Amino Acid ◽  
Wide Range

Lactoferrin is an 80 kDa iron binding protein found in the secretory fluids of mammals and it plays a major role in host defence. An antimicrobial peptide, lactoferrampin, was identified through sequence analysis of bovine lactoferrin and its antimicrobial activity against a wide range of bacteria and yeast species is well documented. In the present work, the contribution of specific amino acid residues of lactoferrampin was examined to evaluate the role that they play in membrane binding and bilayer disruption. The structures of all the bovine lactoferrampin derivatives were examined with circular dichroism and nuclear magnetic resonance spectroscopy, and their interactions with phospholipids were evaluated with differential scanning calorimetry and isothermal titration calorimetry techniques. From our results it is apparent that the amphipathic N-terminal helix anchors the peptide to membranes with Trp 268 and Phe 278 playing important roles in determining the strength of the interaction and for inducing peptide folding. In addition, the N-terminal helix capping residues (DLI) increase the affinity for negatively charged vesicles and they mediate the depth of membrane insertion. Finally, the unique flexibility in the cationic C-terminal region of bovine lactoferrampin does not appear to be essential for the antimicrobial activity of the peptide.

scholarly journals Thermal and Chemical Unfolding of a recombinant monoclonal IgG1 antibody: Application of the Multi-State Zimm-Bragg Theory

2019 ◽  
Author(s):  
P. Garidel ◽  
A. Eiperle ◽  
M. Blech ◽  
J. Seelig
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibody ◽  
Differential Scanning Calorimetry ◽  
Amino Acid ◽  
Quantitative Description ◽  
Thermal Unfolding ◽  
Scanning Calorimetry ◽  
Main Transition ◽  
Binding Enthalpy ◽  
Dsc Thermograms

AbstractThe thermal unfolding of a recombinant monoclonal antibody IgG1 (mAb) was measured with differential scanning calorimetry (DSC). The DSC thermograms reveal a pre-transition at 72°C with an unfolding enthalpy of ΔHcal ∼ 200-300 kcal/mol and a main transition at 85 °C with an enthalpy of ∼900 - 1000 kcal/mol. In contrast to single-domain molecules, mAb unfolding is a complex reaction that is analysed with the multi-state Zimm-Bragg theory. For the investigated mAb, unfolding is characterised by a cooperativity parameter σ ∼10−4 and a Gibbs free energy of unfolding of gnu ∼100 cal/mol per amino acid. The enthalpy of unfolding provides the number of amino acid residues v participating in the unfolding reaction. On average, v∼220±50 amino acids are involved in the pre-transition and v∼850±30 in the main transition, accounting for ∼90% of all amino acids. Thermal unfolding was further studied in the presence of guanidineHCl. The chemical denaturant reduces the unfolding enthalpy ΔHcal and lowers the midpoint temperature T0. Both parameters depend linearly on the concentration of denaturant. The guanidineHCl concentrations needed to unfold mAb at 25 °C are predicted to be 2-3 M for the pre-transition and 5-7 M for the main transition, varying with pH. GuanidineHCl binds to mAb with an exothermic binding enthalpy, which partially compensates the endothermic mAb unfolding enthalpy. The number of guanidineHCL molecules bound upon unfolding is deduced from the DSC thermograms. The bound guanidineHCl-to-unfolded amino acid ratio is 0.79 for the pre-transition and 0.55 for the main transition. The pre-transition binds more denaturant molecules and is more easily destabilised than the main transition.Overall, the current study shows the strength of the Zimm-Bragg model for the quantitative description of unfolding events of large, therapeutic proteins, such as a monoclonal antibody.Statement of significanceFirst quantitative thermodynamic study of an antibody with differential scanning calorimetry and analyzed with the multi-state Zimm-Bragg theory.

Sign in / Sign up

Export Citation Format

Share Document