WAP(version 2.0): an updated computing and visualization server for water molecules

2008 ◽  
Vol 41 (5) ◽  
pp. 952-954 ◽  
Author(s):  
S. Praveen ◽  
J. Ramesh ◽  
P. Sivasankari ◽  
G. Sowmiya ◽  
K. Sekar

By exploiting the fast-growing Internet technology, the interactive computing serverWater Analysis Package(WAP, version 2.0) has been updated with more flexible options to better understand the role of the water O atoms present in three-dimensional macromolecular (protein or nucleic acid) structures. The updated robust server facilitates the computation and visualization of water molecules from various hydration shells, interfacial water molecules and those water molecules that stabilize various secondary structural elements. It is also possible to detect the interactions of water molecules with various parts (polar atoms, nonpolar atoms, main-chain and side-chain atoms) of the protein molecule. Furthermore, a molecular graphics visualization program is interfaced to display the nature of the interactions of the water molecules. The Protein Data Bank archive interfaced with the server is updated every week; hence users get to analyse the latest structures. The computing server can be obtained from http://dicsoft2.physics.iisc.ernet.in/wap/.

2009 ◽  
Vol 43 (1) ◽  
pp. 196-199 ◽  
Author(s):  
K. Hemavathi ◽  
M. Kalaivani ◽  
A. Udayakumar ◽  
G. Sowmiya ◽  
J. Jeyakanthan ◽  
...  

MIPS (metal interactions in protein structures) is a database of metals in the three-dimensional macromolecular structures available in the Protein Data Bank. Bound metal ions in proteins have both catalytic and structural functions. The proposed database serves as an open resource for the analysis and visualization of all metals and their interactions with macromolecular (protein and nucleic acid) structures. MIPS can be searchedviaa user-friendly interface, and the interactions between metals and protein molecules, and the geometric parameters, can be viewed in both textual and graphical format using the freely available graphics plug-inJmol. MIPS is updated regularly, by means of programmed scripts to find metal-containing proteins from newly released protein structures. The database is useful for studying the properties of coordination between metals and protein molecules. It also helps to improve understanding of the relationship between macromolecular structure and function. This database is intended to serve the scientific community working in the areas of chemical and structural biology, and is freely available to all users, around the clock, at http://dicsoft2.physics.iisc.ernet.in/mips/.


2019 ◽  
Vol 52 (6) ◽  
pp. 1422-1426
Author(s):  
Rajendran Santhosh ◽  
Namrata Bankoti ◽  
Adgonda Malgonnavar Padmashri ◽  
Daliah Michael ◽  
Jeyaraman Jeyakanthan ◽  
...  

Missing regions in protein crystal structures are those regions that cannot be resolved, mainly owing to poor electron density (if the three-dimensional structure was solved using X-ray crystallography). These missing regions are known to have high B factors and could represent loops with a possibility of being part of an active site of the protein molecule. Thus, they are likely to provide valuable information and play a crucial role in the design of inhibitors and drugs and in protein structure analysis. In view of this, an online database, Missing Regions in Polypeptide Chains (MRPC), has been developed which provides information about the missing regions in protein structures available in the Protein Data Bank. In addition, the new database has an option for users to obtain the above data for non-homologous protein structures (25 and 90%). A user-friendly graphical interface with various options has been incorporated, with a provision to view the three-dimensional structure of the protein along with the missing regions using JSmol. The MRPC database is updated regularly (currently once every three months) and can be accessed freely at the URL http://cluster.physics.iisc.ac.in/mrpc.


Author(s):  
Gabriel Jan Abrahams ◽  
Janet Newman

Crystallization is in many cases a critical step for solving the three-dimensional structure of a protein molecule. Determining which set of chemicals to use in the initial screen is typically agnostic of the protein under investigation; however, crystallization efficiency could potentially be improved if this were not the case. Previous work has assumed that sequence similarity may provide useful information about appropriate crystallization cocktails; however, the authors are not aware of any quantitative verification of this assumption. This research investigates whether, given current information, one can detect any correlation between sequence similarity and crystallization cocktails. BLAST was used to quantitate the similarity between protein sequences in the Protein Data Bank, and this was compared with three estimations of the chemical similarities of the respective crystallization cocktails. No correlation was detected between proteins of similar (but not identical) sequence and their crystallization cocktails, suggesting that methods of determining screens based on this assumption are unlikely to result in screens that are better than those currently in use.


2006 ◽  
Vol 17 (07) ◽  
pp. 1037-1053 ◽  
Author(s):  
J. SIÓDMIAK ◽  
A. GADOMSKI

We discuss the results of a computer simulation of the biopolymer crystal growth and aggregation based on the 2D lattice Monte Carlo technique and the HP approximation of the biopolymers. As a modeled molecule (growth unit) we comparatively consider the previously studied non-mutant lysozyme protein, Protein Data Bank (PDB) ID: 193L, which forms, under a certain set of thermodynamic-kinetic conditions, the tetragonal crystals, and an amyloidogenic variant of the lysozyme, PDB ID: 1LYY, which is known as fibril-yielding and prone-to-aggregation agent. In our model, the site-dependent attachment, detachment and migration processes are involved. The probability of growth unit motion, attachment and detachment to/from the crystal surface are assumed to be proportional to the orientational factor representing the anisotropy of the molecule. Working within a two-dimensional representation of the truly three-dimensional process, we also argue that the crystal grows in a spiral way, whereby one or more screw dislocations on the crystal surface give rise to a terrace. We interpret the obtained results in terms of known models of crystal growth and aggregation such as B-C-F (Burton-Cabrera-Frank) dislocation driven growth and M-S (Mullins-Sekerka) instability concept, with stochastic aspects supplementing the latter. We discuss the conditions under which crystals vs non-crystalline protein aggregates appear, and how the process depends upon difference in chemical structure of the protein molecule seen as the main building block of the elementary crystal cell.


2010 ◽  
Vol 66 (2) ◽  
pp. 116-124 ◽  
Author(s):  
Jeyaraman Jeyakanthan ◽  
Shankar Prasad Kanaujia ◽  
Yuya Nishida ◽  
Noriko Nakagawa ◽  
Surendran Praveen ◽  
...  

Asymmetric diadenosine tetraphosphate (Ap4A) hydrolases degrade the metabolite Ap4A back into ATP and AMP. The three-dimensional crystal structure of Ap4A hydrolase (16 kDa) fromAquifex aeolicushas been determined in free and ATP-bound forms at 1.8 and 1.95 Å resolution, respectively. The overall three-dimensional crystal structure of the enzyme shows an αβα-sandwich architecture with a characteristic loop adjacent to the catalytic site of the protein molecule. The ATP molecule is bound in the primary active site and the adenine moiety of the nucleotide binds in a ring-stacking arrangement equivalent to that observed in the X-ray structure of Ap4A hydrolase fromCaenorhabditis elegans. Binding of ATP in the active site induces local conformational changes which may have important implications in the mechanism of substrate recognition in this class of enzymes. Furthermore, two invariant water molecules have been identified and their possible structural and/or functional roles are discussed. In addition, modelling of the substrate molecule at the primary active site of the enzyme suggests a possible path for entry and/or exit of the substrate and/or product molecule.


2021 ◽  
Vol 7 (10) ◽  
pp. eabf2558
Author(s):  
J. Dedic ◽  
H. I. Okur ◽  
S. Roke

Hyaluronan (HA) is an anionic, highly hydrated bio-polyelectrolyte found in the extracellular environment, like the synovial fluid between joints. We explore the extended hydration shell structure of HA in water using femtosecond elastic second-harmonic scattering (fs-ESHS). HA enhances orientational water-water correlations. Angle-resolved fs-ESHS measurements and nonlinear optical modeling show that HA behaves like a flexible chain surrounded by extended shells of orientationally correlated water. We describe several ways to determine the concentration-dependent size and shape of a polyelectrolyte in water, using the amount of water oriented by the polyelectrolyte charges as a contrast agent. The spatial extent of the hydration shell is determined via temperature-dependent measurements and can reach up to 475 nm, corresponding to a length of 1600 water molecules. A strong isotope effect, stemming from nuclear quantum effects, is observed when light water (H2O) is replaced by heavy water (D2O), amounting to a factor of 4.3 in the scattered SH intensity.


2012 ◽  
Vol 68 (6) ◽  
pp. m824-m825 ◽  
Author(s):  
Ichraf Chérif ◽  
Jawher Abdelhak ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss

In the crystal structure of the title compound, (C5H6ClN2)[Cr(C2O4)2(H2O)2]·1.5H2O, the CrIII atom adopts a distorted octahedral geometry being coordinated by two O atoms of two cis water molecules and four O atoms from two chelating oxalate dianions. The cis-diaquadioxalatochromate(III) anions, 2-amino-5-chloropyridinium cations and uncoordinated water molecules are linked into a three-dimensional supramolecular array by O—H...O and N—H...O hydrogen-bonding interactions. One of the two independent lattice water molecules is situated on a twofold rotation axis.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Miraslau L. Barabash ◽  
William A. T. Gibby ◽  
Carlo Guardiani ◽  
Alex Smolyanitsky ◽  
Dmitry G. Luchinsky ◽  
...  

AbstractIn order to permeate a nanopore, an ion must overcome a dehydration energy barrier caused by the redistribution of surrounding water molecules. The redistribution is inhomogeneous, anisotropic and strongly position-dependent, resulting in complex patterns that are routinely observed in molecular dynamics simulations. Here, we study the physical origin of these patterns and of how they can be predicted and controlled. We introduce an analytic model able to predict the patterns in a graphene nanopore in terms of experimentally accessible radial distribution functions, giving results that agree well with molecular dynamics simulations. The patterns are attributable to a complex interplay of ionic hydration shells with water layers adjacent to the graphene membrane and with the hydration cloud of the nanopore rim atoms, and we discuss ways of controlling them. Our findings pave the way to designing required transport properties into nanoionic devices by optimising the structure of the hydration patterns.


2020 ◽  
Vol 5 (7) ◽  
Author(s):  
Lucas Paul ◽  
Celestin N. Mudogo ◽  
Kelvin M. Mtei ◽  
Revocatus L. Machunda ◽  
Fidele Ntie-Kang

AbstractCassava is a strategic crop, especially for developing countries. However, the presence of cyanogenic compounds in cassava products limits the proper nutrients utilization. Due to the poor availability of structure discovery and elucidation in the Protein Data Bank is limiting the full understanding of the enzyme, how to inhibit it and applications in different fields. There is a need to solve the three-dimensional structure (3-D) of linamarase from cassava. The structural elucidation will allow the development of a competitive inhibitor and various industrial applications of the enzyme. The goal of this review is to summarize and present the available 3-D modeling structure of linamarase enzyme using different computational strategies. This approach could help in determining the structure of linamarase and later guide the structure elucidation in silico and experimentally.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 180
Author(s):  
Zorana Lopandić ◽  
Luka Dragačević ◽  
Dragan Popović ◽  
Uros Andjelković ◽  
Rajna Minić ◽  
...  

Fluorescently labeled lectins are useful tools for in vivo and in vitro studies of the structure and function of tissues and various pathogens such as viruses, bacteria, and fungi. For the evaluation of high-mannose glycans present on various glycoproteins, a three-dimensional (3D) model of the chimera was designed from the crystal structures of recombinant banana lectin (BanLec, Protein Data Bank entry (PDB): 5EXG) and an enhanced green fluorescent protein (eGFP, PDB 4EUL) by applying molecular modeling and molecular mechanics and expressed in Escherichia coli. BanLec-eGFP, produced as a soluble cytosolic protein of about 42 kDa, revealed β-sheets (41%) as the predominant secondary structures, with the emission peak maximum detected at 509 nm (excitation wavelength 488 nm). More than 65% of the primary structure was confirmed by mass spectrometry. Competitive BanLec-eGFP binding to high mannose glycans of the influenza vaccine (Vaxigrip®) was shown in a fluorescence-linked lectin sorbent assay (FLLSA) with monosaccharides (mannose and glucose) and wild type BanLec and H84T BanLec mutant. BanLec-eGFP exhibited binding to mannose residues on different strains of Salmonella in flow cytometry, with especially pronounced binding to a Salmonella Typhi clinical isolate. BanLec-eGFP can be a useful tool for screening high-mannose glycosylation sites on different microorganisms.


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