Evidence for water binding to the Fe center in cytochrome P450cam obtained by 17O ESEEM, 1H four-pulse ESEEM and pulsed ENDOR

P. m. r. relaxation times ( T 1 and T 2 ) have been measured as a function of regain and temperature for water sorbed by lyophilized methaemoglobin. The purpose of the work was to gain information regarding the nature and extent of water binding by the protein molecules. The T 1 results are interpreted in terms of an exchange between the sixth ligand position of the Fe (III) and other adsorption sites on the protein. At high temperatures the relaxation rate at a given regain reaches a limiting value which allows the fraction of ferric ions hydrated to be calculated. Above 16% regain all the Fe (III) is hydrated. At 21 and 35% regains a maximum appears in the relaxation rate at about -46 °C indicating a contribution from a more mobile phase which produces a T 1 minimum at that temperature. The T 2 data are consistent with a model in which the main contribution to the transverse relaxation rate comes from a tightly bound fraction of the water with ω 0 Ƭ c ≫1. The temperature dependence of T 2 exhibits three different regions: ( a ) a low temperature region where lg T 2 ∝ T -1 ; ( b ) an intermediate region with a steeper increase of T 2 with temperature; and ( c ) a high temperature where T 2 levels off.

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Water Binding Stabilizes Stacked Conformations of Ferrocene Containing Sheet-like Aromatic Oligoamides

Organic & Biomolecular Chemistry ◽

10.1039/d1ob00580d ◽

2021 ◽

Author(s):

Ya-zhou Liu ◽

Xiao Mu ◽

Chieh-Kai Chan ◽

Koen Robeyns ◽

Cheng-Chung Wang ◽

...

Keyword(s):

Essential Role ◽

Water Clusters ◽

Water Binding ◽

Biological Structures ◽

The Stability

While water clusters play an essential role in the stability of biological structures, their ability to stabilize synthetic oligomers is less understood. We have synthesized a heptameric sheet-like aromatic oligoamide...

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In Vivo Analysis of the Biocompatibility and Bone Healing Capacity of a Novel Bone Grafting Material Combined with Hyaluronic Acid

International Journal of Molecular Sciences ◽

10.3390/ijms22094818 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4818

Author(s):

Annica Pröhl ◽

Milijana Batinic ◽

Said Alkildani ◽

Michael Hahn ◽

Milena Radenkovic ◽

...

Keyword(s):

Bone Substitute ◽

Sham Operation ◽

Bone Substitute Material ◽

Water Binding ◽

Sham Operation Group ◽

Operation Group ◽

Substitute Material ◽

Tissue Reactions ◽

Inflammatory Tissue

The present in vivo study analyses both the inflammatory tissue reactions and the bone healing capacity of a newly developed bone substitute material (BSM) based on xenogeneic bone substitute granules combined with hyaluronate (HY) as a water-binding molecule. The results of the hyaluronate containing bone substitute material (BSM) were compared to a control xenogeneic BSM of the same chemical composition and a sham operation group up to 16 weeks post implantationem. A major focus of the study was to analyze the residual hyaluronate and its effects on the material-dependent healing behavior and the inflammatory tissue responses. The study included 63 male Wistar rats using the calvaria implantation model for 2, 8, and 16 weeks post implantationem. Established and Good Laboratory Practice (GLP)-conforming histological, histopathological, and histomorphometrical analysis methods were conducted. The results showed that the new hyaluronate containing BSM was gradually integrated within newly formed bone up to the end of the study that ended in a condition of complete bone defect healing. Thereby, no differences to the healing capacity of the control BSM were found. However, the bone formation in both groups was continuously significantly higher compared to the sham operation group. Additionally, no differences in the (inflammatory) tissue response that was analyzed via qualitative and (semi-) quantitative methods were found. Interestingly, no differences were found between the numbers of pro- and anti-inflammatory macrophages between the three study groups over the entire course of the study. No signs of the HY as a water-binding part of the BSM were histologically detectable at any of the study time points, altogether the results of the present study show that HY allows for an optimal material-associated bone tissue healing comparable to the control xenogeneic BSM. The added HY seems to be degraded within a very short time period of less than 2 weeks so that the remaining BSM granules allow for a gradual osteoconductive bone regeneration. Additionally, no differences between the inflammatory tissue reactions in both material groups and the sham operation group were found. Thus, the new hyaluronate containing xenogeneic BSM and also the control BSM have been shown to be fully biocompatible without any differences regarding bone regeneration.

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Water molecules at protein–drug interfaces: computational prediction and analysis methods

Chemical Society Reviews ◽

10.1039/d0cs00151a ◽

2021 ◽

Author(s):

Marley L. Samways ◽

Richard D. Taylor ◽

Hannah E. Bruce Macdonald ◽

Jonathan W. Essex

Keyword(s):

Computational Prediction ◽

Water Molecules ◽

Protein Drug ◽

Water Binding ◽

Computational Approaches ◽

Analysis Methods

In this review we examine computational approaches to explore the structure and thermodynamics of water binding in protein–drug complexes

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The Hydration Characteristics, Structural Properties and Volatile Profile of Squid (Symplectoteuthis oualaniensis) Mantle Muscle: Impacts of Steaming, Boiling, and Sous Vide Cooking

Foods ◽

10.3390/foods10071646 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1646

Author(s):

Hong Xiao ◽

Nannan Li ◽

Longtao Yan ◽

Yong Xue

Keyword(s):

Structural Properties ◽

Cooking Methods ◽

Volatile Components ◽

Volatile Profile ◽

Proton Mobility ◽

Water Binding ◽

Damage Degree ◽

Application Potential ◽

Sous Vide ◽

Hydration Characteristics

Herein, the effects of boiling (BO), steaming (ST), and sous vide (SV) on the hydration characteristics, structural properties, and volatile profile of squid (Symplectoteuthis oualaniensis) mantle muscle (SMM) were investigated. Three cooking methods resulted in a dramatic decrease in proton mobility and freedom of protons, the relaxation time T2 decreased after cooking, and the water binding in the SMM was closer, but the SV treatment could retain more water in the SMM. SV resulted in a lower cooking loss (10.8%) than ST (49.0%) and BO (36.7%). Samples treated with SV had a better color and texture, the secondary structure β-fold of the squid protein was damaged by cooking to a certain extent, and the damage degree was BO > ST > SV. Compared with BO and ST, SV treatment caused more damage to the myosin heavy chain, paramyosin, and actin in SMM, improved the tenderness of SMM, and resulted in more regular internal reticular structures and less formation of fibrous structures. Cooking methods can significantly affect the volatile components of SMM, resulting in increasing volatile components or generating new volatile components in SMM including 2-methylbutanal, ethyl 2-methylpropanoate, acetic acid, and propyl methyl ketone in ST and BO samples and 2-methylbutanal, hexanal, and 2,3-pentanedione in SV samples. Therefore, SV resulted in the best quality squids and has substantial industrial application potential.

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Impact of high-pressure homogenization on the microstructure and rheological properties of citrus fiber

International Journal of Food Engineering ◽

10.1515/ijfe-2020-0206 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Dianbin Su ◽

Xin-Di Zhu ◽

Yong Wang ◽

Dong Li ◽

Li-Jun Wang

Keyword(s):

Particle Size ◽

High Pressure ◽

Rheological Properties ◽

Binding Capacity ◽

Loss Modulus ◽

High Pressure Homogenization ◽

Carreau Model ◽

Hydration Properties ◽

Water Binding ◽

Water Holding

Abstract Citrus fiber dispersion with different concentrations (5–25 g/kg) was treated by high-pressure homogenization (90 and 160 MPa) for two cycles. The particle size distribution, hydration properties of powders, morphology and rheological measurements were carried out to study the microstructure and rheological properties changes by high-pressure homogenization (HPH). In conclusion, the HPH can reduce the particle size of fiber, improve the water holding capacity and water binding capacity. Furthermore, fiber shape can be modified from globular cluster to flake-like slices, and tiny pores can be formed on the surface of citrus fiber. The apparent viscosity, storage modulus and loss modulus were increased by HPH whereas the activation energy was reduced. The Hershcel–Bulkley model, Carreau model and Power Law mode were selected to evaluate the rheological properties.

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