eChapters

Introduction

Proteins are the most abundant organic compounds constituting major part of the body. Chemically, proteins are nitrogen containing macromolecules and polymers of L α-amino acids, which serve a wide range of structural and biological functions in animal body. For example, connective tissue made up of collagen, metabolicenzymes, neuro transmitters,signal in gmolecules, structural components of cell membranes and cell organelles, etc. all are chemically proteins.

Before goinginto the details of protein metabolism, first, we need to understand that there are majorly two sources of proteins in our body: dietary protein and body protein. Dietary protein is taken in diet, while body protein indicates the protein and amino acids synthesized in animal body to fulfill the requirements for growth and development. The digestion of proteins will not be discussed here as it has been described in detail in chapter 12. Dietary protein is digested in presence of several enzymes such as trypsin, pepsin, chymotrypsin, aminopeptidases and carboxypeptidases and is converted into mono-, di- and oligopeptides in stomach and small intestine; and finally converted into amino acids. These amino acids are transported to the systemthrough intestinal mucosa via active transport, from where they enter into the cells for further metabolism. Therefore, ‘metabolismof proteins’ is more appropriatelylearnt as ‘metabolism of amino acids’.

Summary

Researchers face a series of similar-yet unique problems to isolate proteins. To solve these they must have dip knowledge to select an appropriate technique. The mechanism, to study the way in which a living system works, is necessary to dismantle the machine and to isolate the component parts so that they may be studied, separately and in their interaction with other parts. The knowledge that is gained in this way may be put to practical use, for example, in the design of medicines, diagnostics, pesticides, or industrial processes. In every case a pure protein is desirable as impurities may either be misleading, dangerous or unproductive, respectively. Protein isolation is, therefore, a very common, almost central, procedure in biotechnology. The purpose of this chapter is thus to fill the beginners with techniques relevant to protein isolation, hopefully to improve their knowledge.

Introduction

All the amino acids have in common an amino group and a carboxyl group attached to the -carbon atom; however, they differ in having distinctive side chains, usually called R groups, as is shown in the following  generalised structural formula

Abstract

The field of bioinformatics emerged as a tool to facilitate biological discoveries more than 10 years ago. Structure prediction is fundamentally different from the inverse problem of protein design. Protein structure prediction is one of the most important goals pursued by bioinformatics and theoretical chemistry; it is highly important in medicine and biotechnology. Structure prediction is fundamentally different from the inverse problem of protein design. While the genome of many organism have been sequenced over the last few year, transforming such raw sequence data into knowledge remains a hard task. A great number of prediction program for genes have been developed hat try to address this problem, which consists of locating the genes along a genome.

1. Introduction

Protein–protein interactions serve as the hub of the functioning of a living cell, coordinate biological processes as well as form core for interactomics system of living organisms. Various biological processes as signal transduction, cell-cell communication, ingestion or expulsion of any macromolecule, host parasite interaction, diseases as cancer and many other metabolic networks employ protein–protein interactions. During such a process two or more proteins interact transiently with each other or form complex for a long period of time. Thus attempts have been made for years to study comprehensive mechanism of such protein–protein interactions by various branches of sciences such as biochemistry, quantum chemistry, molecular dynamics, chemical biology and signal transduction. The availability of three-dimensional (3D) structure of proteins is a prerequisite for understanding functions of protein complexes at a molecular level as well as amino acid interactions within a complex.

Abstract

The field of bioinformatics emerged as a tool to facilitate biological discoveries more than 10 years ago. The ability to capture, manage, process, analyze and interpret data became more important than ever. Bioinformatics in agricultural science has many complex aspects and problems that must be resolved due to the involvement of a wide variety of fields and subjects. Consequently, the establishment of interdisciplinary research areas is required, which should include collaboration among experimental and informatics researchers in different fields within industry, academia, and government. Thus, the Agricultural Bioinformatics Special Interest Group was established to promote interaction among researchers and provide an opportunity to report on bioinformatics studies in agricultural science: design and analysis of functional foods, scientific testing of food safety, breeding of agricultural organisms, development of environmental friendly agricultural chemicals, bioremediation and production of useful chemical materials using microorganisms, measuring and monitoring biodiversity, statistical genetics in resource ecology, and so on. The activities of the Agricultural Bioinformatics Special Interest Group include (1) Studies of applied bioinformatics in the agricultural science (2) Development of new research areas in agricultural science using bioinformatics (3) Practical application of bioinformatics technologies in the field of agricultural science (4) Development of new bioinformatics technologies characteristic of agricultural science.

Abstract

Proteins are complex molecules composed of one or more polypeptide chains made up of amino acid residues. These molecules perform a variety of essential functions in living organisms, including DNA replication, molecule transport, catalyzing metabolic processes, and providing structural support to cells. In this chapter, we explore the four levels of protein structure: primary, secondary, tertiary, and quaternary. Primary structure refers to the specific sequence of amino acids in a polypeptide chain, while secondary structure describes the folding of the chain into alpha-helices, beta-sheets, or other patterns. Tertiary structure is the three-dimensional shape of a single polypeptide chain, and quaternary structure refers to the interactions between multiple polypeptide chains to form a larger protein complex. Additionally, this chapter covers various methods used to predict protein structure, including homology modeling, ab initio prediction, and threading algorithms.

Abstract

Protein-protein interactions play a major role in most cellular processes. Many essential cellular processes such as signal transduction, transport, cellular motion and most regulatory mechanisms are mediated by protein-protein interactions. The study of protein-protein interactions is of great importance in determining the biological function and impact of proteins. The experimental techniques remain expensive, time-consuming and labor-intense. Computational methods play an important role at all the stages of determining protein-protein interactions. In this chapter, we describe the different types of protein-protein interactions, computational methods, currently available databases and tools, protein-protein docking and as well as protein-protein interactions as drug targets.

Proteinase inhibitors (PIs) are small proteins that are quite common in nature. They are natural, defense-related proteins often present in seeds and induced in certain plant tissues by herbivory or wounding (Koiwa et al., 1997). PIs are present in multiple forms in numerous tissues of animals and plants as well as in microorganisms. In plants they can be counted among the defensive mechanisms displayed against phytophagous insects and microorganisms. The defensive capacities of plant PIs rely on inhibition of proteases present in insect guts or secreted by microorganisms, causing a reduction in the availability of amino acids necessary for their growth and development. PIs are of common occurrence in the plant kingdom. Plant PIs (PPIs) are generally small proteins that have mainly been described as occurring in storage tissues, such as tubers and seeds, but they have also been found in the aerial parts of plants (De Leo et al., 2002). One of the important defense strategies that are found in plants to combat predators involve PIs which are in particular effective against phytophagous insects and microorganisms. The defensive capabilities of PPIs rely on inhibition of proteases present in insect guts or secreted by microorganisms, causing a reduction in the availability of amino acids necessary for their growth and development (Lawrence and Koundal, 2002).

Proteins are large biological molecules, or macromolecules, consisting of one or more chains of amino acid residues. Proteins perform a vast array of functions within living organisms, including catalysing metabolic reactions, replicating DNA, responding to stimuli, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in folding of the protein into a specific three-dimensional structure that determines its activity. A polypeptide is a single linear polymer chain derived from the condensation of amino acids. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residues in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the genetic code specifies 20 standard amino acids; however, in certain organisms the genetic code can include selenocysteine and, in certain archaea-pyrrolysine. Shortly after or even during synthesis, the residues in a protein are often chemically modified by post translational modification, which alters the physical and chemical properties, folding, stability, activity, and ultimately, the function of the proteins. Sometimes proteins have non-peptide groups attached, which can be called prosthetic groups or cofactors. Proteins can also work together to achieve a particular function, and they often associate to form stable protein complexes.

Like other biological macromolecules such as pollysaccharides and nucleic acids, proteins are essential parts of organisms and participate in virtually every process within cells. Many proteins are enzymes that catalyse biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, which form a system of scaffolding that maintains cell shape. Other proteins are important in cell signalling, immune responses, cell adhesion, and the cell cycle. Proteins are also necessary in animals’ diets, since animals cannot synthesize all the amino acids they need and must obtain essential amino acids from food. Through the process of digestion, animals break down ingested protein into free amino acids that are then used in metabolism.

INTRODUCTION

Plants are rich source of nutrients for most of the organisms including microbes' arthropods and vertebrates. There are various biotic viz. insects, weeds and pathogens and abiotic factors viz. temperature, humidity, salinity etc. that causes harm to plants. For yield loss due to pest EIL (Economic injury levels) calculation is important (Stern et al, 1959). EIL calculation will define economic damage (yield losses equal to management costs) in calculable terms. Since plants are sessile they cannot move to avoid the menace of these factors, but they have developed a unique way of structural, chemical, and protein-based defences which are specifically designed to detect and inhibit invading organisms before they are able to cause extensive damage. In response to the incitations by the pathogens some genes are activated which in turn codes for defence proteins (Grennan, 2006). Understanding how plants defend themselves from pathogens and herbivores is essential in order to protect our livelihood and nutritional security. In addition to proteins, plant anatomy and some of the ecological relationship also plays an important role in plant defense mechanism. Induction of plant resistance against fungi and bacteria was reported in 1900.

The word protein was first coined in 1838 to emphasize the importance of this class of molecules. The word is derived from the Greek word proteios which means “of the first- rank”. Proteins are polymers/macro molecules made up of several amino acids. When there are more than 50 amino acids in a chain, the polypeptide is normally called a protein. Each protein in the cells of living beings has a unique sequence of amino acids that determines its biological function. The proteins are folded into specific defined structures, which are maintained by a large number of relatively weak bonds. The  three  dimensional structure is well defined and suited to it’s specific function.

Very small changes in the structure can modify the function. Hence, it is important to know the structure of proteins to understand their behavior and function. The biological activity of proteins depends on maintenance of folded conformation. Proteins fold into well defined three dimensional shapes and they are able to recognize their corresponding substrates or antigen molecules and bind them tightly. The protein structure has been classified into four different levels based on the folded conformation of the protein.

Proteins are composed of amino acids and are large molecules that play a crucial role in various biological processes. They are considered the fundamental building blocks of life due to their abundance in the body, constituting approximately 60% of the dry weight of cells. These complex biomolecules are intricately folded and twisted strands of amino acids, actively participating in vital life processes, including metabolism, locomotion, immune response intercellular signaling, and molecular identification. As macronutrients proteins are present in all living organisms and directly contribute to numerous metabolic pathways. It is important to note that proteins are unique to each organism, exhibit species specificity, and vary within different organs of the same organism. With 22 different amino acids, the properties of a protein molecule are determined by the specific arrangement of these amino acids. While plants can synthesize all the necessary amino acids for protein production, animals rely on external sources for certain amino acids. Proteins consist of amino acids connected through peptide bonds, formed by the linkage between the amino (NH2 ) group of one amino acid and the carboxyl (COOH) group of another amino acid.

1. INTRODUCTION

Proteins are polymers of amino acids. Twenty different types of amino acids occur naturally in proteins. Proteins differ from each other according to the type, number and sequence of amino acids that make up the polypeptide backbone. Proteins are the important constituents of foods for a number of reasons. They are a major source of energy, as well as containing essential amino-acids, like lysine, tryptophan, methionine, leucine, isoleucine and valine which are essential to human health, but which the body cannot synthesize. Proteins are also the major structural components of many natural foods, often determining their overall texture, e.g., tenderness of meat or fish products. Isolated proteins are often used in foods as ingredients because of their unique functional properties, i.e., their ability to provide desirable appearance, texture or stability.

Proteins are complex organic molecules made up of carbon, hydrogen, oxygen, and nitrogen. Most proteins also contain sulphur and phosphorus and also play an important role in food preparation. The final quality of many food products are influenced by how the proteins are treated while food is being prepared.

1.    The basic building block(s) of proteins is/are

(a) Amino acids

(b) Phenolics

(c) Carboxylic acids

(d) Fatty acids

2.    Alpha helix and ?- pleated sheet are characteristic of protein structure?

(a) Primary

(b) Secondary

(c) Tertiary

(d) Quaternary

Introduction

Aquatic ecosystems are critical components of the global environment and provide a variety of resources for human population, including food, water for drinking and irrigation, recreational opportunities, and habitat for economically important fisheries. Fish is the main source of animal protein for 3 billion people worldwide, providing a valuable protein complement to the food platter worldwide. Fish is also an important source of essential vitamins and fatty acids. Furthermore, it provides an important source of cash income for many poor households and holds a great potential as a source of foreign exchange. However, aquatic ecosystems are increasingly being threatened directly and indirectly by climate change. Global warming with consequent climate variability and extreme weather conditions has a great impact on the aquatic ecosystems resulting in increased temperature variation, ocean acidification and freshwater salinization etc. As per report of IPCC 2018, global warming of 1.5 ºC above pre-industrial levels has been declared (IPCC, 2018) and expected to rise further in future. Thus, variations in temperature, salinity, acidity and dissolved oxygen along with the effects of other anthropogenic activities may exert strong in?uences on aquatic ecosystems and the aquatic animls will be facing these climate-related stressors in near future. Such environmental stressors is projected to alter fundamental ecological processes, geographic distribution of aquatic species, reproductive and immunological performance of species etc.

The genera Proteus and Providencia belong to the tribe Proteae of the family Enterobacteriaeceae. The members of both these genera are gram negative, motile bacilli, aerobes and facultative anaerobes and can grow on basic media. A characteristic feature which distinguishes tribe Proteae from other members of Enterobactereaceae is the presence of the enzyme phenylalanine-deaminase which converts phenylalanine to phenylpyruvic acid (PPA reaction).They also produces a powerful urease enzyme which rapidly hydrolyses urea to ammonia.
Genus Proteus
They are gram-negative bacilli, 1-3 μm long and 0.6 μm wide. They are noncapsulated and are actively motile by peritrichous flagella. The name ‘Proteus’ refers to their pleomorphism, after the Greek God Proteus who could assume any shape. Four species: Proteus mirabilis, P.vulgaris, P.penneri and P.myxofaciens are recognized. Proteus mirabilis, P.vulgaris are widely recognised as human pathogens.
Culture Characteristics
These can grow on ordinary media like nutrient agar with a characteristic fishy or seminal odour. On MacConkey and Teepol lactose agar, lactose nonfermenting pale colonies, around 2-3 mm in size are formed. On non-inhibitory solid media such as blood and nutrient agar Proteus mirabilis and P vulgaris show characteristic swarming growth in the form of a uniform film, which spreads over the whole surface of the plate. In young swarming cultures, many of the bacteria are long, curved and filamentous, sometimes reaching upto 80 μm in length. When two different strains of swarming proteus mirabilis encounter one another on an agar plate, swarming ceases and a visibile line of demarcation forms. This is known as the Dienes phenomenon. In liquid medium (peptone water, nutrient broth), Proteus produces uniform
turbidity with a slight powdery deposit and an ammoniacal odour.

1.    Collect the bone marrow from iliac crest of rabbit, dog, goat and sheep; sternum of pigs by 16-18 G bone marrow biopsy needle under sedation/anesthesia and maintain strict asepsis protocol
2.    To aspirate bone marrow, negative pressure should create in the syringe by pulling back the plunger. Syringe should be first flushed with heparin before bone marrow collection
3.    Collect approximately 2.5-5 ml of bone marrow from each animal
4.    Mix the bone marrow sample with equal volume of low DMEM having 10% FBS and 1 ml of PS and then layer on 5 ml of histopaque/Ficol-Paque Plus in a falcon tube
5.    Centrifuge at 3000 rpm for 30 min
6.    Collect stem cells from the interface with the help of a micropipette
7.    Cells wash thrice with DPBS 
8.    Centrifuged at 2000 rpm for 5 min