scholarly journals The Eigenproblem Translated for Alignment of Molecules

Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1027 ◽  
Author(s):  
Lorentz Jäntschi
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Molecular Conformation ◽  
Living Cells ◽  
Molecular Alignment ◽  
Cartesian Coordinates ◽  
Naturally Occurring ◽  
Cartesian System ◽  
Glycolysis Pathway ◽  
Living Organisms

Molecular conformation as a subproblem of the geometrical shaping of the molecules is essential for the expression of biological activity. It is well known that from the series of all possible sugars, those that are most naturally occurring and usable by living organisms as a source of energy—because they can be phosphorylated by hexokinase, the first enzyme in the glycolysis pathway—are D-sugars (from the Latin dextro). Furthermore, the most naturally occurring amino acids in living cells are L-sugars (from the Latin laevo). However, a problem arises in dealing with the comparison of their conformers. One alternative way to compare sugars is via their molecular alignment. Here, a solution to the eigenproblem of molecular alignment is communicated. The Cartesian system is rotated, and eventually translated and reflected until the molecule arrives in a position characterized by the highest absolute values of the eigenvalues observed on the Cartesian coordinates. The rotation alone can provide eight alternate positions relative to the reflexes of each coordinate.

A water soluble glucopyranosyl conjugate as a selective and reactive probe for cysteine in a buffer and its application to living cells

The Analyst ◽  
2015 ◽  
Vol 140 (21) ◽  
pp. 7391-7398 ◽  
Author(s):  
Sivaiah Areti ◽  
Rohit Teotia ◽  
Chebrolu Pulla Rao
Keyword(s):  
Amino Acids ◽  
Cell Imaging ◽  
Living Cells ◽  
Water Soluble ◽  
Biological Cells ◽  
Green Fluorescence ◽  
Naturally Occurring

A water soluble and biocompatible glucopyranosyl conjugate (L) has been synthesized, characterized and shown to be selective to Cys among the naturally occurring amino acids. TheLshows green fluorescence upon reaction with –SH containing molecules present in biological cells and hence provides cell imaging.

Epigenetic Mechanisms of Maternal Dietary Protein and Amino Acids Affecting Growth and Development of Offspring

2019 ◽  
Vol 20 (7) ◽  
pp. 727-735 ◽  
Author(s):  
Yi Wu ◽  
Zhibin Cheng ◽  
Yueyu Bai ◽  
Xi Ma
Keyword(s):  
Amino Acids ◽  
Dna Methylation ◽  
Dietary Protein ◽  
Growth And Development ◽  
Later Life ◽  
Biological Macromolecules ◽  
Epigenetic Mechanisms ◽  
Maternal Circulation ◽  
Energy Processing ◽  
Living Organisms

Nutrients can regulate metabolic activities of living organisms through epigenetic mechanisms, including DNA methylation, histone modification, and RNA regulation. Since the nutrients required for early embryos and postpartum lactation are derived in whole or in part from maternal and lactating nutrition, the maternal nutritional level affects the growth and development of fetus and creates a profound relationship between disease development and early environmental exposure in the offspring’s later life. Protein is one of the most important biological macromolecules, involved in almost every process of life, such as information transmission, energy processing and material metabolism. Maternal protein intake levels may affect the integrity of the fetal genome and alter DNA methylation and gene expression. Most amino acids are supplied to the fetus from the maternal circulation through active transport of placenta. Some amino acids, such as methionine, as dietary methyl donor, play an important role in DNA methylation and body’s one-carbon metabolism. The purpose of this review is to describe effects of maternal dietary protein and amino acid intake on fetal and neonatal growth and development through epigenetic mechanisms, with examples in humans and animals.

Naphthoquinone Derivatives Isolated from Plants: Recent Advances in Biological Activity

2020 ◽  
Vol 20 (19) ◽  
pp. 2019-2035
Author(s):  
Esmaeil Sheikh Ahmadi ◽  
Amir Tajbakhsh ◽  
Milad Iranshahy ◽  
Javad Asili ◽  
Nadine Kretschmer ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Biological Activity ◽  
Small Molecules ◽  
Anticancer Activity ◽  
Clinical Significance ◽  
Phase Ii ◽  
Biological Activities ◽  
Phase Ii Clinical Trials ◽  
Naturally Occurring ◽  
The Subject

Naturally occurring naphthoquinones (NQs) comprising highly reactive small molecules are the subject of increasing attention due to their promising biological activities such as antioxidant, antimicrobial, apoptosis-inducing activities, and especially anticancer activity. Lapachol, lapachone, and napabucasin belong to the NQs and are in phase II clinical trials for the treatment of many cancers. This review aims to provide a comprehensive and updated overview on the biological activities of several new NQs isolated from different species of plants reported from January 2013 to January 2020, their potential therapeutic applications and their clinical significance.

Synthesis and Biological Activity of Embelin and its Derivatives: An Overview

2020 ◽  
Vol 20 (5) ◽  
pp. 396-407 ◽  
Author(s):  
Zhaojun Sheng ◽  
Siyuan Ge ◽  
Min Gao ◽  
Rongchao Jian ◽  
Xiaole Chen ◽  
...  
Keyword(s):  
Biological Activity ◽  
Biological Effects ◽  
New Drugs ◽  
Hydroxyl Groups ◽  
Carbonyl Groups ◽  
Cellular Mechanisms ◽  
Embelia Ribes ◽  
Naturally Occurring ◽  
Ic50 Value ◽  
Apoptosis Protein

Embelin is a naturally occurring para-benzoquinone isolated from Embelia ribes (Burm. f.) of the Myrsinaceae family, and contains two carbonyl groups, a methine group and two hydroxyl groups. With embelin as the lead compound, more than one hundred derivatives have been reported. Embelin is well known for its ability to antagonize the X-linked inhibitor of apoptosis protein (XIAP) with an IC50 value of 4.1 μM. The potential of embelin and its derivatives in the treatment of various cancers has been extensively studied. In addition, these compounds display a variety of other biological effects: antimicrobial, antioxidant, analgesic, anti-inflammatory, anxiolytic and antifertility activity. This paper reviews the recent progress in the synthesis and biological activity of embelin and its derivatives. Their cellular mechanisms of action and prospects in the research and development of new drugs are also discussed.

Synthesis and biological activity of new metallocenic angiotensin II analogs

1988 ◽  
Vol 53 (11) ◽  
pp. 2914-2919 ◽  
Author(s):  
Pierrette Maes ◽  
Annie Ricouart ◽  
Emmanuel Escher ◽  
André Tartar ◽  
Christian Sergheraert
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Angiotensin Ii ◽  
Solid Phase ◽  
Rabbit Aorta ◽  
Phase Method ◽  
Solid Phase Method

Analogs of angiotensin II in which phenylalanine in position 8 was replaced with cymantrenylalanine or with its triphenylphosphine photosubstitution product were synthesized by the solid-phase method. On rabbit aorta strips, these peptides were found to be pure antagonists of angiotensin II. Their relative affinities are higher than most other analogs substituted in position 8 with bulky amino-acids.

scholarly journals Transforming growth factor alpha: mutation of aspartic acid 47 and leucine 48 results in different biological activities.

1988 ◽  
Vol 8 (3) ◽  
pp. 1247-1252 ◽  
Author(s):  
E Lazar ◽  
S Watanabe ◽  
S Dalton ◽  
M B Sporn
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Amino Acid ◽  
Growth Factor ◽  
Aspartic Acid ◽  
Transforming Growth Factor ◽  
Biologically Active ◽  
Single Amino Acid ◽  
Transforming Growth Factor Alpha ◽  
Factor Alpha

To study the relationship between the primary structure of transforming growth factor alpha (TGF-alpha) and some of its functional properties (competition with epidermal growth factor (EGF) for binding to the EGF receptor and induction of anchorage-independent growth), we introduced single amino acid mutations into the sequence for the fully processed, 50-amino-acid human TGF-alpha. The wild-type and mutant proteins were expressed in a vector by using a yeast alpha mating pheromone promoter. Mutations of two amino acids that are conserved in the family of the EGF-like peptides and are located in the carboxy-terminal part of TGF-alpha resulted in different biological effects. When aspartic acid 47 was mutated to alanine or asparagine, biological activity was retained; in contrast, substitutions of this residue with serine or glutamic acid generated mutants with reduced binding and colony-forming capacities. When leucine 48 was mutated to alanine, a complete loss of binding and colony-forming abilities resulted; mutation of leucine 48 to isoleucine or methionine resulted in very low activities. Our data suggest that these two adjacent conserved amino acids in positions 47 and 48 play different roles in defining the structure and/or biological activity of TGF-alpha and that the carboxy terminus of TGF-alpha is involved in interactions with cellular TGF-alpha receptors. The side chain of leucine 48 appears to be crucial either indirectly in determining the biologically active conformation of TGF-alpha or directly in the molecular recognition of TGF-alpha by its receptor.

scholarly journals Translational and Structural Requirements of the Early Nodulin Gene enod40, a Short-Open Reading Frame-Containing RNA, for Elicitation of a Cell-Specific Growth Response in the Alfalfa Root Cortex

2001 ◽  
Vol 21 (1) ◽  
pp. 354-366 ◽  
Author(s):  
Carolina Sousa ◽  
Christina Johansson ◽  
Celine Charon ◽  
Hamid Manyani ◽  
Christof Sautter ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Rna Structure ◽  
Open Reading Frames ◽  
In Vitro Translation ◽  
Cortical Cells ◽  
Root Cortex ◽  
Reading Frame ◽  
Early Nodulin

ABSTRACT A diversity of mRNAs containing only short open reading frames (sORF-RNAs; encoding less than 30 amino acids) have been shown to be induced in growth and differentiation processes. The early nodulin geneenod40, coding for a 0.7-kb sORF-RNA, is expressed in the nodule primordium developing in the root cortex of leguminous plants after infection by symbiotic bacteria. Ballistic microtargeting of this gene into Medicago roots induced division of cortical cells. Translation of two sORFs (I and II, 13 and 27 amino acids, respectively) present in the conserved 5′ and 3′ regions ofenod40 was required for this biological activity. These sORFs may be translated in roots via a reinitiation mechanism. In vitro translation products starting from the ATG of sORF I were detectable by mutating enod40 to yield peptides larger than 38 amino acids. Deletion of a Medicago truncatula enod40 region between the sORFs, spanning a predicted RNA structure, did not affect their translation but resulted in significantly decreased biological activity. Our data reveal a complex regulation of enod40action, pointing to a role of sORF-encoded peptides and structured RNA signals in developmental processes involving sORF-RNAs.

scholarly journals Regulation of rat magnocellular neurosecretory system by D-aspartate: evidence for biological role(s) of a naturally occurring free D-amino acid in mammals

2000 ◽  
Vol 167 (2) ◽  
pp. 247-252 ◽  
Author(s):  
H Wang ◽  
H Wolosker ◽  
J Pevsner ◽  
SH Snyder ◽  
DJ Selkoe
Keyword(s):  
Gene Expression ◽  
Amino Acids ◽  
Amino Acid ◽  
Physiological Function ◽  
Neurosecretory System ◽  
Milk Ejection ◽  
Magnocellular Neurons ◽  
Rat Hypothalamus ◽  
Naturally Occurring

Little evidence is available for the physiological function of D-amino acids in species other than bacteria. Here we demonstrate that naturally occurring freed -aspartate (D-Asp) is present in all magnocellular neurons of rat hypothalamus. The levels of this naturally occurring D-amino acid were elevated during lactation and returned to normal thereafter in the magnocellular neurosecretory system, which produces oxytocin, a hormone responsible for milk ejection during lactation. Intraperitoneal injections of D-Asp reproducibly increased oxytocin gene expression and decreased the concentration of circulating oxytocin in vivo. Similar changes were observed in the vasopressin system. These results provide evidence for the role(s) of naturally occurring free D-Asp in mammalian physiology. The findings argue against the conventional concept that only L-stereoisomers of amino acids are functional in higher species.

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