Increasing sequence length favors .alpha.-helix over 310-helix in alanine-based peptides: Evidence for a length-dependent structural transition

Biochemistry ◽  
1993 ◽  
Vol 32 (45) ◽  
pp. 11957-11962 ◽  
Author(s):  
Wayne R. Fiori ◽  
Siobhan M. Miick ◽  
Glenn L. Millhauser
Author(s):  
Atul Rawal ◽  
Kristen L. Rhinehardt ◽  
Ram V. Mohan

Abstract Collagen is a pervasive, triple helical, extracellular matrix (ECM) protein, found in human body from skin and bones to blood vessels and lungs, making it biocompatible, biodegradable, capable of cell attachment, and relevant for applications in bio-polymers, tissue engineering and a plethora of other bio-medical fields. Natural collagen’s extraction from natural sources is time consuming, sometimes costly, and it is difficult to render, and could present undesired biological and pathogenic changes. Nanoscale collagen mimetic peptides (Synthetic Collagen), without the unwanted biological entities present in the medium, has shown to mimic the unique properties that are present in natural collagen. Synthetic collagen, thus provides a superior alternative compared to natural collagen for its utilization in several applications. Their properties are affected by surrounding environments, including various solvents, and can be tailored toward specific applications. The focus of this paper is to investigate the mechanical properties of these nanoscale collagen mimetic peptides with lengths of about 10nm, leading to understanding of their feasibility in bio-printing of a composite polymeric collagen biomaterial with a blend of multiple synthetic collagen molecules. Molecular dynamics modeling is used to simulate, model and analyze mechanical properties of synthetic collagen peptides. In particular, mechanical behavior of these peptides are studied. An in-depth insight into the deformation and structural properties of the collagen peptides are of innovative significance for a multitude of bio medical engineering applications. Present paper employed steered molecular dynamics as the principal method of investigating the mechanical properties of nanoscale collagen mimetic peptide 1BKV, which closely resembles natural collagen with a shorter sequence length of 30 amino acids. A detailed comprehension of the protein’s mechanical properties is investigated through fraying deformation behavior studied. A calculated Gibbs free energy value of 40 Kcal/mol corresponds with a complete unfolding of a single alpha-helix peptide chain from a triple helical protein in case of fraying. Force needed for complete separation of the alpha-helix from the triple-helical protein is analyzed, and discussed in this paper.


1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)


2020 ◽  
Vol 17 (1) ◽  
pp. 40-50
Author(s):  
Farzane Kargar ◽  
Amir Savardashtaki ◽  
Mojtaba Mortazavi ◽  
Masoud Torkzadeh Mahani ◽  
Ali Mohammad Amani ◽  
...  

Background: The 1,4-alpha-glucan branching protein (GlgB) plays an important role in the glycogen biosynthesis and the deficiency in this enzyme has resulted in Glycogen storage disease and accumulation of an amylopectin-like polysaccharide. Consequently, this enzyme was considered a special topic in clinical and biotechnological research. One of the newly introduced GlgB belongs to the Neisseria sp. HMSC071A01 (Ref.Seq. WP_049335546). For in silico analysis, the 3D molecular modeling of this enzyme was conducted in the I-TASSER web server. Methods: For a better evaluation, the important characteristics of this enzyme such as functional properties, metabolic pathway and activity were investigated in the TargetP software. Additionally, the phylogenetic tree and secondary structure of this enzyme were studied by Mafft and Prabi software, respectively. Finally, the binding site properties (the maltoheptaose as substrate) were studied using the AutoDock Vina. Results: By drawing the phylogenetic tree, the closest species were the taxonomic group of Betaproteobacteria. The results showed that the structure of this enzyme had 34.45% of the alpha helix and 45.45% of the random coil. Our analysis predicted that this enzyme has a potential signal peptide in the protein sequence. Conclusion: By these analyses, a new understanding was developed related to the sequence and structure of this enzyme. Our findings can further be used in some fields of clinical and industrial biotechnology.


Neuropeptides ◽  
2016 ◽  
Vol 57 ◽  
pp. 71-83 ◽  
Author(s):  
Mohammed Inayathullah ◽  
Aaron Tan ◽  
Rebecca Jeyaraj ◽  
James Lam ◽  
Nam-Joon Cho ◽  
...  

2021 ◽  
Vol 3 (2) ◽  
pp. 605-610
Author(s):  
Chang-Yong Kim ◽  
Tetiana Slusar ◽  
Jinchul Cho ◽  
Hyun-Tak Kim

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