Alice CMS

More than 750 amino acids have been discovered in Nature. Bacteria, fungi and algae and other plants provide nearly all these, which exist either in the free form or bound up into larger molecules (as constituents of peptides and proteins and other types of amide, and of alkylated and esterified structures).

The twenty amino acids that are utilised in living cells for protein synthesis under the control of genes are in a special category since they are fundamental to all life forms as building blocks for peptides and proteins.

In chemistry, an amino acid is a molecule containing both amine and carboxyl functional groups.

Amino acids exist in either D (dextro) or L (levo) form (stereoisomers). The D and L refer to the absolute confirmation of optically active compounds. With the exception of glycine, all other amino acids are mirror images that can not be superimposed. Most of the amino acids found in nature are of the L-type. Hence, eukaryotic proteins are always composed of L-amino acids although D-amino acids are found in bacterial cell walls and in some peptide antibiotics.

Amino acids are classified into two groups: essential amino acids and nonessential amino acids. An essential amino acid or indispensable amino acid cannot be made by the body and must be supplied by food. These include isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Another amino acid - histidine is considered semi-essential because the body does not always require dietary sources of it.

Nonessential amino acids are made by the body from the essential amino acids or normal breakdown of proteins. The nonessential amino acids are arginine, alanine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, proline, serine, and tyrosine.

The classification of an amino acid as essential or nonessential does not reflect its importance, because all 20 amino acids are necessary for health.

Alpha-amino acids are the building blocks of proteins. Amino acids combine in a condensation reaction, that is, through dehydration synthesis, that releases water and the new “amino acid residue” that is held together by a peptide bond. Proteins are defined by their unique sequence of amino acid residues; this sequence is the primary structure of the protein. Just as the letters of the alphabet can be combined to form an almost endless variety of words, amino acids can be linked in varying sequences to form a vast variety of proteins.

Peptides and proteins play a wide variety of roles in living organisms and display a range of properties (from the potent hormonal activity of some small peptides to the structural support and protection for the organism shown by insoluble proteins).

The physiological importance of alpha amino acids ensures a sustained interest in their chemistry – particularly in pharmaceutical exploration for new drugs, and for their synthesis, reaction and physical properties. As is often the case when the chemistry of a biologically important class of compounds is being vigorously developed, an increasing range of uses has been identified for alpha amino acids in the wider context of stereoselective laboratory synthesis. Continue reading »

The Definition Of Chemistry and Its Main Sections

Chemistry - one of the most important and vast areas of natural science, science of substances and their properties, structure and the transformation occurring as a result of chemical reactions. Since all matter consists of atoms, which due to chemical bonds are able to form molecules, the chemistry studies basically interactions between atoms and molecules as the result of such interactions.
The subject of chemistry is the chemical elements and compounds, as well as regularities, which subordinate various chemical reactions.

Sections
The modern chemistry is a vast area of natural science and many of its sections are essentially independent, but closely related scientific disciplines.
On the basis of studied objects (substances) chemistry is divided into inorganic and organic. Physical chemistry explains the essence of chemical phenomena and their common patterns based on physical principles and experimental data. It includes quantum chemistry, electrochemistry, chemical thermodynamics, and chemical kinetics. Separate sections are also an analytical and colloid chemistry.

The technological basis of modern industry are presented by chemical engineering that is a science of saving methods and means of industrial chemical processing of finished natural materials and obtaining of artificial chemical products that cannot be found in nature.
The combination of chemistry with other related natural sciences constitutes biochemistry, bioorganic chemistry, geochemistry, radiation chemistry, photochemistry, etc.

Organic Chemistry is the section of chemistry, studying the structure, properties, methods of synthesis of organic compounds and reactions among them.
The subject of organic chemistry includes the following goals, experimental methods and theoretical presentations:
• Allocation of individual substances from plant, animal or fossil raw materials
• Synthesis and purification of compounds
• Determining the structure of matter
• Defining the mechanisms of chemical reactions
• Identifying the links between the structure of organic substances and their properties

Analytical Chemistry is the section of chemistry, studying the chemical composition and structure of matter. The subject of it as a science is to improve existing and develop new methods of analysis, their practical application, and the study of theoretical foundations of analytical methods. Analytical chemistry is divided into a qualitative analysis aimed at determining what or what substance, in what form are there in the sample, and quantitative analysis aimed at determining how much of the substance (of elements, ions, molecular forms, etc.) is there in the sample.

Determination of elemental composition of material objects is known as elemental analysis. Establishing the structure of chemical compounds and mixtures at the molecular level is called molecular analysis. One of the molecular analyses of chemical compounds is a structural analysis which studies the spatial atomic structure of matter, the empirical formula, molecular weight, etc. The tasks of analytical chemistry are to determine the characteristics of organic, inorganic and bio-chemical facilities. Analysis of organic compounds according to functional groups is called functional analysis.

Continue reading »

Peptide research on drug design and drug discovery is one of the most promising fields in the development of the new drugs.

Peptide sequences are constituents of larger proteins, where they are responsible for molecular recognition and biological activities. Inhibition of protein-protein interactions by peptides and the evolution of peptide ligands to small molecule mimetics is a major goal of the field, with several notable successes. Peptides would therefore seem to be ideal drug leads. However, peptides are limited in that they are metabolically unstable due to the protease cleavage of the peptide backbone and have poor bioavailability, in part due to low membrane transport characteristics of the peptide’s amide backbone structure.

The starting point for a peptide mimetics research is the identification of a peptide or

peptide sequence within a protein context that is activ in the relevant assay. The process involves deconstructing the original peptide and reassembling the essential features on a new, mimetic scaffold that retains the ability to interact with the biological target, but circumvents the problems associated with a natural peptide. The deconstruction

process begins by developing structure-activity relationships, then designing analogs to

define a minimal active sequence and to identify the key residues and portions of the

backbone in the peptide that are responsible for the biological effect. The structural

constraints are added to check the effectivity of these features.

The interaction of a peptide with a biological target may occur via a direct binding of a

linear sequence in any number of conformations accessible to a peptide.

The modern peptide mimetics approach incorporates a production of small molecules which mimic peptides in order to overcome their ineffectiveness as drugs when administered orally. The small molecules mimetics retain the desired biological properties of the peptide lead, but are metabolically stable, have unlimited diversity, and can be designed to provide the new drugs.

By this process, the peptide has been reduced to its information content, the basis for a pharmacophore model that defines the critical features and their arrangement in space. This model supports the re-assembly of the critical elements and non-peptide variants on a modified scaffold that presents the optimized pharmacophore to the receptor. The optimized peptide-hybrid may be valuable as a first drug candidate, in addition to its role as a tool for further evolution to a mimetic. Mimetic scaffolds are designed to be resistant to the proteases that would destroy a natural peptide, and would have pharmaceutical properties consistent with a drug candidate.

It is possible to represent the biologically active sites of the peptides in the form of orally administered small-molecule mimietics that take all the advantages of evolutionally designed peptides on the one hand and have good drug properties, are stable, bioavailable, inexpensive in manufacture and convenient in use, on the other hand. There is no way to get involved in modern drug discovery and drug design without peptide and their small molecule mimetics research.

Continue reading »

Medication discovery and development is a costly process owing to the high expenses of Research and Development and man clinical experiments. You may see that a price of medical development needs form US$ 897 million to US$ 1.9 billion. Often the entire procedure lasts from ten to fifteen years. First of all in the research process chemists are to find a target (e.g. protein) and than take different drugs that can interact with this target. Clinical experiments are the most extensive and expensive phase in drug development and is done in order to get the needed government approvals. Every US medication ought to receive special approval from Food and Drug Administration (FDA). As one can find drug discovery & development is a high-priced and prolongs process today.

Chemists utilize the method of interacting the target with different compounds to identify the greatest drug candidate. They get a target protein and observe the interaction of it with compounds that they have in special compound library. This examination is often done in so called high-throughput screening (HTS) facilities. There are also commercially accessible compound libraries that contain various compounds up to a few thousands of exemplars. Compounds that become the most active ones are called hits. Such exemplars wonderfully interreact with the target. Then these hits may become chief compounds that are utilized for different transformations and as a result are utilized for greater interactions and less side effects.

Scientists have two means of drug design & discovery nowadays. There are given a few modes of discovering medication candidate and you could see their pros and cons:

1. Virtual screening (VS) founded on the computing deduced or simulated genuine screening;

This method has such advantages:

- low prices, no compounds have to be bought externally or synthesized by a chemist;

- chemists can research various compounds that are still in project;

- guiding high-throughput screening experiments is high priced and virtual screening can be utilized to reduce the initial number of compounds before utilizing HTS methods;

- it has a huge list of chemicals that scientists may utilize.

The quantity of probable virtual elements accessible for VS is exceedingly greater than the quantity of compounds that are accessible for HTS. But we must claim about the shortage of VS. That is inability to see real interaction of compounds.

2. HTS is a real screening and it may utilize a huge amount of elements per day. So researchers get real outcome during this way of medication discovery. But it requires huge funds.

These means show the interaction of a given target (protein) with different compounds. They can be applied to help build theories about required chemical properties when designing the medication and, moreover, they may be used to improve and transform drug candidates. The next three VS or computational means are used in the nowadays drug discovery procedure: Molecular Docking, Quantitative Structure-Activity Relationships (QSAR) and Pharmacopoeia Mapping. To get much more information about drug discovery service utilize our website. Continue reading »

Modern human society lives and continues developing. It actively uses the scientific and technical advances and it seems to be a point of no return. Science has been working to gain more knowledge about the visual environment and various processes that occur there. The whole science has been divided to several classes: natural sciences, exact sciences, social sciences, etc. Every such class is subdivided on several subclasses. But among the variety of sciences there are some leading sciences and sciences that fall behind. The sciences that are developed more than others are medicine and biology.

Sciences that are related to providing some biological inventions into medicine develop a lot and supported by many organization. Today medicine tries not only to use some preparations of the new generation and practice new elements but also uses some techniques of treatments that allow to affect the illness in its initial stage or even before it starts. It has become to be possible owing to the researches of molecular mechanisms of many illnesses. Some methods can perform the correction of abnormalities by means of normalizing the processes that occur in the organism. The problems of development of food, medicines and other substances related to active introduction of some modern biotechnologies. However such tangible process of biology wouldn’t be able without close cooperation with other kinds of science.

It is a fact that among the wide range of different chemicals the most important for organism are the ions of sodium, zinc, copper and iron. If the amounts these elements deviate form the norm it can cause some significant consequences. For example it can be the disorder of metabolism. So the origin of a great deal of illnesses is just deviation of concentration of some substances from norm. It is connected to the principle of processes’ behavior inside a cell. Most of substances are important as a element that takes part in definite chemical reaction.

In the maintaining of normal vita functions the organic molecules play quite important role. There are several types of organic molecules that are comprised in every organism. They are biological macromolecules, oligomers and monomers. For chemistry the most important thing is establishing of relations between the structure of the matter and its characteristics, especially biological effect. For these purposes the great arsenal of knowledge gained by mathematics, physics, chemistry and biology is used.

Today there are a lot of scientific centers that carry out a lot of different chemical and biological researches. They can also carry out any drug discovery if it is requested by some medical organizations.

The most significant problem that has been studied by the chemical biology is the synthesis of proteins and nucleic acids. Excepting a huge amount of medical preparations there are a lot of achievements of chemistry that can be met in our daily life. Some new food products appear and the new methods of their proper retention have been improved constantly.

Continue reading »

Peptides are polymers that connect and glue amino acids together with the help of what is called a peptide bond.  When many peptides form a molecule, it is called a protein or a polypeptide molecule. When peptides are analyzed, researches look at the amino acids that are present and at their ratios.

There is a common rule that peptide chains of limited length that allows people to conduct peptide synthesis from amino acids are not called proteins but rather peptides.  However, as science gets better and better at producing ever larger peptide chains, this naming convention no longer reflects the status quo.

Peptides are classified on the basis of how they are created. The first class of peptides are generated from the translation of messenger ribonucleic acid. They are called ribosomal peptides. To reach maturity they are often subjected to digestion by enzymes. This process is known as proteolysis. In higher creatures ribosomal peptides may serve as hormones or even signaling substances.

There are peptides which are put together by their individual enzyme characteristics rather than by the ribosome. These peptides are called nonribosomal. One example of a nonribosomal peptide is glutathione which performs antioxidant functions in some organisms. Some plants feature nonribosomal peptides as well. They synthesize nonribosomal peptides via nonribosomal peptide synthetases.

Scientists can get another class of peptides known as peptones from milk and digested meat. When bacteria or fungi are grown in a dish, peptones are used to nurture them.

Peptides have become very important in molecular biological research, because they contribute to the production of peptide antibodies in animals without the need to have a pure protein under the examination. Antigenic peptides can be synthesized for just a section of the necessary protein. Later these sections help to create antibodies in the animals.

One more explanation for increased scientific interest to peptides is that they are successfully used in mass spectrometry.  Mass spectrometry is a technique which allows researchers to identify specific proteins by their mass and sequence.

Peptides also help researches study and uncover new and existing proteins and their functions. Researches create peptides, conduct experiments where interactions between peptides and proteins occur and use these empirical findings to improve our understanding of various illnesses. For example, inhibitory peptides are used in the study of cancer.

Continue reading »