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Introduction and Background
Published in Jay L. Nadeau, Introduction to Experimental Biophysics, 2017
The ribosome produces a one-dimensional polypeptide chain that is biologically inactive. This is referred to as the protein’s primary structure (Figure 1.19a). The secondary structure results from hydrogen bonding and creates typical forms such as alpha helices and beta sheets (Figure 1.19b). The tertiary structure is the final three-dimensional form and results from all of the intermolecular interactions among the amino acid residues in the context of the correct temperature, pH, and ionic concentration (Figure 1.19c). A correctly folded protein is called the native conformation. Some proteins have a quaternary structure, which refers to the assembly of multiple subunits that fold independently (Figure 1.19d).
Stability optimization of orthovanadate nanoparticles in biocompatible media
Published in Journal of Dispersion Science and Technology, 2022
Nataliya Kavok, Vladimir Klochkov, Katheryna Averchenko, Ganna Grygorova, Olga Sedyh, Svetlana Yefimova
Such studies are particularly important for understanding the influence of NPs on the function of specialized biomolecules, for which any change in conformation can lead to functional changes. Thus, thorough molecular studies were aimed at studying the interaction of cerium NPs with hemoglobin, insulin, and dsDNA as model biomolecules.[54,55] According to the data obtained cerium NPs affect the conformation of hemoglobin and insulin, as well as demonstrate binding along major and minor grooves with dsDNA. At the same time, cerium NPs was encapsulated in the structure accompanied by a decrease in alpha-helices and an increase in protein beta-sheets. Thus, the binding activity of cerium NPs to proteins affected their conformational structure with subsequent unfolding.
The Crotalaria juncea metal transporter CjNRAMP1 has a high Fe uptake activity, even in an environment with high Cd contamination
Published in International Journal of Phytoremediation, 2018
Tsugumi Nakanishi-Masuno, Nobukazu Shitan, Akifumi Sugiyama, Kojiro Takanashi, Shoko Inaba, Shuji Kaneko, Kazufumi Yazaki
RT-PCR with degenerate primer pairs designed from amino acid sequences conserved in NRAMP members (Figure 1(a)) yielded amplicons from total RNA of C. juncea leaves significantly similar to NRAMPs. A full-length cDNA of the NRAMP homolog (designated CjNRAMP1) was isolated by 5′ and 3′ RACE. The deduced amino acid sequence of CjNRAMP1 consisted of 537 amino acids, with 75% amino acid sequence identity to the A. thaliana Fe/Cd/Mn transporter AtNRAMP1. Use of the SOSUI program (http://bp.nuap.nagoya-u.ac.jp/sosui/) to identify hydrophobic domains indicated that the CjNRAMP1 protein had 12 putative transmembrane alpha-helices. The polypeptide sequence of CjNRAMP1 protein possessed a conserved region characteristic of NRAMP transporters and called the consensus transport motif (CTM) between the transmembrane alpha-helices VIII and IX. Phylogenetic analysis of plant NRAMP members showed that CjNRAMP1 belonged to a subgroup containing AtNRAMP1 and AtNRAMP6.
Zinc(II)-Schiff base complex functionalized on gold nanospheres: synthesis, characterization, anticancer study and interaction with proteins
Published in Journal of Coordination Chemistry, 2022
Yin Zhuang Ng, Kong Wai Tan, Lip Yong Chung, Fatimah Salim, May Lee Low, Ing Hong Ooi, Foo Win Yip, Chew Hee Ng
Circular dichroism (CD) is commonly used to elucidate the modifications of the secondary structure of proteins which resulted from interaction with small molecules [63]. As BSA is composed of 62% alpha-helices, 13% beta-sheets, 14% beta-turns and 11% random structures, its spectrum is mainly that of α-helical structure of the protein [31]. The CD spectrum of BSA at pH 7.4 usually showed two negative minima in the UV region at 208 and 222 nm, which were the characteristic bands for α-helical configuration of proteins [27, 64]. The negative band at 208 nm was due to the exciton splitting of the lowest peptide π–π* transition, while the negative band at 220 nm was due to the peptide n-π* transition.