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Cellular and Immunobiology
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Masood Moghul, Sarah McClelland, Prabhakar Rajan
Structural proteins (e.g., collagen, keratin)Provide form and structure both within and between cells.
Basic genetics and patterns of inheritance
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
In autosomal dominant genetic disorders, only one copy of a mutant allele is necessary for expression of the disease (Fig. 16). Thus, heterozygotes will be affected. The risk of passing on the mutation to an offspring is 50% for each pregnancy. Vertical transmission of the disorder is seen on pedigree analysis, and the condition can often be traced back many generations. However, there are certain caveats to keep in mind when evaluating autosomal dominant disorders. First, there is a high degree of variability of expression of dominant conditions. Even within the same family, some individuals may be severely affected while others may have very mild and medically insignificant features. Thus, thorough review of medical histories and physical examinations on multiple family members are often parts of a genetic evaluation. Second, there may be reduced penetrance of a dominant disorder. Thus, a heterozygote may not show any manifestations of the mutant gene after a complete medical evaluation. Finally, many autosomal dominant disorders have a high new spontaneous mutation rate and a dominant condition may appear de novo in an isolated individual in a pedigree. However, once present, it can be passed on to subsequent generations. In general, abnormal genes in autosomal dominant disorders likely encode structural proteins, such as collagen, which is abnormal in osteogenesis imperfecta, or fibrillin, which is mutant in Marfan syndrome.
Genetic Limitations to Athletic Performance
Published in Peter M. Tiidus, Rebecca E. K. MacPherson, Paul J. LeBlanc, Andrea R. Josse, The Routledge Handbook on Biochemistry of Exercise, 2020
ACTN3 is perhaps the best-known sports performance gene. It is often referred to as the sprinting gene. It is a muscle structural protein primarily expressed in type II (fast) skeletal muscle fibres. There, it binds to the actin thin filaments, anchoring them at the Z discs between the sarcomeres where it is crucial for muscle function and contraction. However, it contains an unusual nonsense polymorphism at amino acid 577 (R577X; Ensembl Variant rs1815739; 56)—unusual in that it is both well tolerated and common in human populations (50). Any variant that results in the absence of a structural protein ought to have a dramatic effect on phenotype, be strongly selected against, and therefore be rare in human populations. However, the effects of this change in ACTN3 are tolerated far better than would be predicted and the underlying polymorphism far more common (∼40% globally) than would be expected. This tolerance appears to be due to overlapping expression patterns and functional redundancy with the related protein ACTN2. ACTN2 can carry out the essential functions of ACTN3, meaning that ACTN3's absence is not so damaging (50). Although, given the ACTN3 R577X association with sporting performance, ACTN2 clearly cannot carry out all of ACTN3's functions equally well.
Plant-Derived Natural Non-Nucleoside Analog Inhibitors (NNAIs) against RNA-Dependent RNA Polymerase Complex (nsp7/nsp8/nsp12) of SARS-CoV-2
Published in Journal of Dietary Supplements, 2023
Sreus A. G. Naidu, Ghulam Mustafa, Roger A. Clemens, A. Satyanarayan Naidu
Hydrogen (H)-bonds are responsible for secondary and tertiary structural protein motifs. In protein environments, redox (H+ proton transfer) reactions occur along polar or charged residues and isolated water molecules. These compounds consist of H-bond networks that serve as redox sensors; therefore, an in-depth understanding of redox mechanism(s) is essential to elucidate H-bond energetics in protein-ligand interactions (61). Since, protons (H+) are redox sensors, the formation of H-bonds between a ligand and a protein motif explains the binding affinity of an inhibitor toward the RdRp protein target in molecular dynamic simulations; accordingly, more number of H-bonds reflect a stronger interaction (62). The active site of the SARS-CoV-2 RdRp is formed by conserved polymerase motifs (A-G), where the motifs A and C have the divalent-cation-binding amino acid Asp618, and the catalytic residues Ser759-Asp760-Asp761, respectively (23). The cellular redox state governs the van der Waals and π-Sulfur interactions with amino acid residues of the catalytic center and the NTP entry channel of the SARS-CoV-2 RdRp-RNA complex (59, 63).
Recent trends in next generation immunoinformatics harnessed for universal coronavirus vaccine design
Published in Pathogens and Global Health, 2023
Chin Peng Lim, Boon Hui Kok, Hui Ting Lim, Candy Chuah, Badarulhisam Abdul Rahman, Abu Bakar Abdul Majeed, Michelle Wykes, Chiuan Herng Leow, Chiuan Yee Leow
Finally, Omicron variant (B.1.1.529) was first reported in South Africa. Mutations are present in ORF1ab protein as well as all structural proteins. In S protein, the number of mutations is strikingly massive, that is 34 mutations, including three deletions and an insertion of three residues at position 214. Unprecedentedly, the RBD also accommodates as many as 15 mutations. For instance, although the glutamic acid at position 484 is substituted by alanine instead of lysine as observed in Beta and Gamma variant, Omicron variant has been reported to exhibit a similar escaping effect from neutralizing antibodies [62]. Q493R and Q498R introduce additional electrostatic interactions and S477N forms hydrogen bonding with ACE2 receptor, increasing the binding affinity towards the receptor [63]. Furthermore, a triple mutation is spotted at the furin cleavage site (H655Y, N679K, and P681H), which may imply an enhancement in the transmissibility [64]. Still, Omicron variant shares some mutations with other VOCs, such as ∆69-70 and N501Y. Table 1 contains all notable mutations observed in these variants [65].
Anti-photoaging effects of flexible nanoliposomes encapsulated Moringa oleifera Lam. isothiocyanate in UVB-induced cell damage in HaCaT cells
Published in Drug Delivery, 2022
Yijin Wang, Qianqian Ouyang, Xuefei Chang, Min Yang, Junpeng He, Yang Tian, Jun Sheng
Proteolytic enzymes such as MMPs and elastases are produced by epidermal keratinocytes and fibroblasts in the mediation of ECM remodeling (Philips et al., 2011). The MMPs initiate the photoaging of the skin by acting as collagenases (Mu et al., 2021). Collagen and elastin are the major structural proteins in the ECM. The basal levels of the enzymes increase under various conditions such as aging; however, they increase considerably more under environmental pollutants and UV radiation. The UV radiation induces high expressions of MMP-1, MMP-3, and MMP-9. MMP-1 is the most important enzyme for degrading the components of the ECM and breaking the normal structure of collagen fibers and elastic fibers; MMP-3 is a stromelysin; and MMP-9 degrades denatured collagens (Quan et al., 2009). The changes of MMP1, MMP3, and MMP9 were not obvious when drugs were stored for one day (Fig. S3), five days (Fig. S4), and 10 days (Figure 10). MMP-1 is the most important enzyme for degrading the components of the ECM and breaking the normal structure of collagen and elastic fibers; MMP-3 is a stromelysin; and MMP-9 degrades denatured collagens. The expressions of MMP-1, MMP-3, and MMP-9 are significantly higher than those of the normal group (p < .05). Further, when treated with HACE/MITC NPs, the expressions were significantly decreased compared with those for the UVB group (p < .05).