scholarly journals Spontaneous Determinants of Protein Aging Mini Review

Author(s):  
Victor Vasilyevich Dyakin ◽  
Vladimir Nikolaevich Uversky

The universal chirality is the commonly accepted view of nature. Biological chirality is the distinct part of the more general phenomena. Following this view, all living organisms are characterized by the non-equilibrium state of their molecular constituents. From the thermodynamic perspective, the non-equilibrium state of biomolecular ensemble holds inevitable consequences being the substrate of spontaneous reactions directed to equilibrium (not associated with life) state. At the protein level, spontaneous biological reactions represent the natural part of proteins' post-translational modifications (PTMs). The essential contribution to the origin and maintenance of the non-equilibrium state belongs to prevalent bio-molecular chirality. Correspondently, spontaneous PTMs such as racemization and glycation, working against life-supporting prevalent chirality, are known as the significant determinants of protein misfolding, dysfunctions, and aggregation. Accumulation of aberrant protein during life-span allows consideration of time-dependent spontaneous racemization and glycation as protein aging. Spontaneous PTMs of proteins is occurring in the interaction with other forms of enzymatic and non-enzymatic PTMs. In this review, we are considering the contribution of spontaneous racemization and non-enzymatic glycosylation to protein aging.

Author(s):  
Victor Vasilyevich Dyakin ◽  
Nika Victorovna Dyakina-Fagnano ◽  
Laura Beth McIntire ◽  
Vladimir Nikolaevich Uversky

In humans, age-associated degrading changes are observed in molecular and cellular processes underly the time-dependent decline in spatial navigation, time perception, cognitive and psy-chological abilities, and memory. Cross talk of biological, cognitive, and psychological clocks provides an integrative contribution to healthy and advanced aging. At the molecular level, ge-nome, proteome, and lipidome instability are widely recognized as the primary causal factors in aging. We narrow attention to the roles of protein aging linked to prevalent amino acids chirali-ty, enzymatic and spontaneous (non-enzymatic) post-translational modifications (PTMs SP), and non-equilibrium phase transitions. The homochirality of protein synthesis, resulting in the steady-state non-equilibrium condition of protein structure, makes them prone to multiple types of enzymatic and spontaneous PTMs, including racemization and isomerization. Spontaneous racemization leads to the loss of the balanced prevalent chirality. Advanced biological aging re-lated to irreversible PTMs SP has been associated with the nontrivial interplay between poor so-matic and mental health conditions. Through stress response systems (SRS), the environmental and psychological stressors contribute to the age-associated “collapse” of protein homochirality. The role of prevalent protein chirality and entropy of protein folding in biological aging is mainly overlooked. In a more generalized context, the time-dependent shift from enzymatic to the non-enzymatic transformation of biochirality might represent an important and yet un-der-appreciated hallmark of aging.


2010 ◽  
Vol 224 (06) ◽  
pp. 929-934 ◽  
Author(s):  
Herbert W. Zimmermann

AbstractWe consider a substance X with two monotropic modifications 1 and 2 of different thermodynamic stability ΔH1 < ΔH2. Ostwald´s rule states that first of all the instable modification 1 crystallizes on cooling down liquid X, which subsequently turns into the stable modification 2. Numerous examples verify this rule, however what is its reason? Ostwald´s rule can be traced back to the principle of the shortest way. We start with Hamilton´s principle and the Euler-Lagrange equation of classical mechanics and adapt it to thermodynamics. Now the relevant variables are the entropy S, the entropy production P = dS/dt, and the time t. Application of the Lagrangian F(S, P, t) leads us to the geodesic line S(t). The system moves along the geodesic line on the shortest way I from its initial non-equilibrium state i of entropy Si to the final equilibrium state f of entropy Sf. The two modifications 1 and 2 take different ways I1 and I2. According to the principle of the shortest way, I1 < I2 is realized in the first step of crystallization only. Now we consider a supercooled sample of liquid X at a temperature T just below the melting point of 1 and 2. Then the change of entropy ΔS1 = Sf 1 - Si 1 on crystallizing 1 can be related to the corresponding chang of enthalpy by ΔS1 = ΔH1/T. Now it can be shown that the shortest way of crystallization I1 corresponds under special, well-defined conditions to the smallest change of entropy ΔS1 < ΔS2 and thus enthalpy ΔH1 < ΔH2. In other words, the shortest way of crystallization I1 really leads us to the instable modification 1. This is Ostwald´s rule.


2013 ◽  
Vol 13 (5) ◽  
pp. 1330-1356 ◽  
Author(s):  
G. H. Tang ◽  
G. X. Zhai ◽  
W. Q. Tao ◽  
X. J. Gu ◽  
D. R. Emerson

AbstractGases in microfluidic structures or devices are often in a non-equilibrium state. The conventional thermodynamic models for fluids and heat transfer break down and the Navier-Stokes-Fourier equations are no longer accurate or valid. In this paper, the extended thermodynamic approach is employed to study the rarefied gas flow in microstructures, including the heat transfer between a parallel channel andpressure-driven Poiseuille flows through a parallel microchannel andcircular microtube. The gas flow characteristics are studied and it is shown that the heat transfer in the non-equilibrium state no longer obeys the Fourier gradient transport law. In addition, the bimodal distribution of streamwise and spanwise velocity and temperature through a long circular microtube is captured for the first time.


2018 ◽  
Vol 1115 ◽  
pp. 022007
Author(s):  
S V Barakhvostov ◽  
N B Volkov ◽  
A I Lipchak ◽  
V P Tarakanov ◽  
S I Tkachenko ◽  
...  

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 650
Author(s):  
Anastasiia I. Petushkova ◽  
Andrey A. Zamyatnin

Proteolytic enzymes play a crucial role in metabolic processes, providing the cell with amino acids through the hydrolysis of multiple endogenous and exogenous proteins. In addition to this function, proteases are involved in numerous protein cascades to maintain cellular and extracellular homeostasis. The redox regulation of proteolysis provides a flexible dose-dependent mechanism for proteolytic activity control. The excessive reactive oxygen species (ROS) and reactive nitrogen species (RNS) in living organisms indicate pathological conditions, so redox-sensitive proteases can swiftly induce pro-survival responses or regulated cell death (RCD). At the same time, severe protein oxidation can lead to the dysregulation of proteolysis, which induces either protein aggregation or superfluous protein hydrolysis. Therefore, oxidative stress contributes to the onset of age-related dysfunction. In the present review, we consider the post-translational modifications (PTMs) of proteolytic enzymes and their impact on homeostasis.


2016 ◽  
Vol 13 (7) ◽  
pp. 690-697 ◽  
Author(s):  
Asif Majeed ◽  
Xiaoxia Zhong ◽  
Shaofeng Xu ◽  
Xinhui Wu ◽  
Uros Cvelbar ◽  
...  

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