User:Clarker1/Protein allergy

Protein allergies are one of the most common allergies, especially seen in young children. A protein is vital to correct to cellular function. Its structure is a polypeptide backbone, and it is made from an amino acid sequence. The folding of the protein is what gives a cell its function. There are four types of weak interactions that create protein folding. A protein can have a variety of functions, depending on its confirmation, determined by the folding of the protein. There are many ways that proteins are regulated in the cell, three of which are feedback inhibition, phosphorylation, and GTP-binging proteins. There are a variety of ways of protein consumption, mainly through food intake. When a person with a protein allergy intakes specific foods, many symptoms can arise. Many symptoms are not severe, however, there are some symptoms that can be extremely dangerous. When an allergic reaction occurs, there are treatments that can terminate the reaction. There are also ways to avoid the foods that cause the reaction, while still being able to maintain a healthy lifestyle.

Protein Structure

A protein is made from a chain of amino acids. There are twenty different amino acids from which a specific sequence can be derived. Each amino acid is linked through a peptide bond. The amino acid sequence of each protein is specific to the protein, but it is the same in each molecule with that determined sequence. A protein can be also be referred to as a polypeptide chain because of peptide bonds connecting each amino acid to the backbone. The polypeptide chain is supported by a backbone. The backbone has two distinct ends, and this is seen throughout all proteins. There is an amino end, also known as the N-terminus of the protein and a carboxyl end, or the C-Terminus. The amino end is marked by an amino group commonly known as NH3, and the carboxyl end is marked by the presence of a carboxyl function group -COO. An amino acid sequence is read from left to right, from N to C terminus. Side chains are attached to the backbone of the amino acids. The side chains differ between amino acids and in fact provide the structure with its polarity. Each side chain on a given amino acid is specific to the individual protein.

Protein Folding

Protein folding is essential to the overall function of the individual protein. The polypeptide chain is often very long and flexible, this leads to a wide variety of ways for a protein to fold. Noncovalent bonds are the only force controlling protein folding. They provide the protein with the power to control their shape and provide structure. While a single noncovalent bond is very weak, a combination of many weak bonds provide the need strength and structure for a given protein.There are three types of noncovalent bonds that aid in protein folding. They are as follows: electrostatic attractions, hydrogen bonds, and van deer Waals attractions. Hydrophobic interactions are often considered a fourth type of weak interaction that hold proteins together.

Another factor that needs to be considered during protein folding is the type of side chains present in the specific amino acid of a protein. Polar and nonpolar side chains can greatly affect the folding of a protein and in turn its function. A polar side chain is known as a hydrophilic side chain. Hydrophilic means "water loving", therefore these specific side chains arrange towards the outside of the structure. This is because they form hydrogen bonds with water and other polar groups. Common polar side chains are:arginine, glutamine, and histidine. (126) In contrast to hydrophilic side chains are those of the nonpolar category which are considered to be hydrophilic side chains or "water hating". Hydrophilic side chains include: phenylalanine, leucine, valine, and trytophan. (126) Hydrophilic side chains attempt to avoid contact with water and other polar molecules, and in turn are often found on the inside of a protein.

The final folded structure of a protein is considered to be the protein's conformation. The needed information for the correct protein folding is found in a proteins amino acid sequence. This sequence allows the protein to fold into is desired three-dimensional shape. This is often considered to be the proteins overall conformation. Proper protein folding is done with the aid of molecular chaperones. These proteins bind to a partially folded chain and help them to fold along the most energetically favored pathway (125). Two common folding patterns seen in proteins are the alpha helix and beta sheets.

How Proteins Work

The conformation of each protein determines the proteins function. the noncovelent bonds previously discussed are what allow for specific protein function. A protein will bind or stick to another molecule. Proteins show a very high amount of specificity when binding to other molecules. A ligand is any substance that binds to a protein. The ability for a ligand to bind to a protein is determined by the surface to which it is binding to. The surface needs to be extremely specific in order for the ligand to bind. The site at which a ligand bonds to a protein is called the proteins binding site. The binding site is usually determined by a set of amino acids specific to the ligand and the protein.

A protein can have a wide variety of functions.

Protein Control

Protein control or regulation occurs at mulitple levels in a variety of ways. Most of which include proteins being siwtched on and off. There are three key ways in which a protein is regulated: Feedback inhibition, Phosphorylation, GTP-binding proteins.

Feedback Inhibition

Feedback inhibition is defined as "an enzyme acting early in a reaction pathway is inhibited by a late product of that pathway. Whenever large quantities of the final product begin to accumulate, the product binds to an earlier enzyme and slows down its catalytic action limiting further entry of substrates to that reaction pathway" (150). Feedback inhibition is considered to be negative regulation. This is because it prevents and blocks an enzyme from acting. In contrast, positive regulation is the activation of an enzyme.

Phosphorylation

Phosphorylation is the process of covalently attaching a phosphate group onto an amino acid side chain. This creates a conformational change that can allow for a change in the binding of ligands to the proteins surface. Phosphorylation is catalyzed by protein kinase. Dephosphorylation is the removal of a phosphate group from an amino acid side chain. This is done by protein phosphatase. Phosphorylation or dephosphorylation is specific to the protein being studied. It may activate or inhibit the protein depending on the amino acid sequence present and the presence of a phosphate group.

GTP-binding proteins

GTP-binding proteins can also change the conformation of a protein which in turn alters protein function. The presence of a bound GTP activates a protein. When that protein is hydrolyzed and the GTP is altered to a GDP the protein is then in an inactive state. This is because through the process of hydrolysis the proteins phosphate group is released and the conformation changes. GTP-binding proteins act as molecular switches for proteins, turning them on and off.

Common Allergy-Causing Foods

Peanuts are a very popular cause of allergic reactions. Peanut allergies can be outgrown by many infants by the time they become school-aged. Not really a nut, peanuts are a member of the bean family. Many people with a peanut allergy do not show signs of an allergic reaction to other types of beans, although tests may show an allergy is present.

Tree nuts grow on trees. Some of these include: pecans, pistachios, pine nuts, and walnuts. A person can show signs of an allergy to one specific type of nut or to many types.

Seeds, including sesame seeds and poppy seeds, contain oils where protein is present, causing an allergic reaction.

Egg allergies affect about one in fifty children. This allergy, however, is commonly lost by the time a child is five. Although allergies can be caused by the yolk, the white part of the egg is typically the major allergy causing portion.

Milk is another popular allergy causing food. Milk allergies can come from cow's milk, goat's milk, or sheep's milk. Many children who cannot tolerate milk also have a hard time tolerating cheese or other products derived from milk. A very small portion of children with a milk allergy, roughly ten percent, will have a reaction to beef. Beef contains a small amount of protein that is present in cow's milk.

Other foods include: soy, wheat, fish, shellfish, fruits, vegetables, spices, synthetic and natural colors, and chemical additives.

Symptoms

Symptoms of allergies vary from person to person. The amount of food needed to trigger a reaction also varies from person to person. Symptoms vary depending on the severity of the allergy, and they can appear in as little as a few minutes or may take up to an hour. Symptoms affect the skin, gastrointestinal tract, and in severe cases, the respiratory tract and blood circulation.

Skin Symptoms

A common skin symptom is hives. Hives are seen as red, itchy bumps. Edema, another common symptom, is the swelling of the skin. Swelling of the eyes and swelling of the lips are also common during an allergic reaction. A less severe symptom is eczema, a dry and bumpy rash, also known as atopic dermatitis. Eczema is a type of skin rash that is inherited and triggered by an irritant, mainly food allergies.

Gastrointestinal Symptoms

These symptoms include: itchy mouth with bumps, stomachache, nausea, vomiting, diarrhea, bloody stool in infants and children, and a taste of metal that lingers in the mouth.

Respiratory and Blood Circulation

Serious danger regarding allergies can begin when the respiratory tract or blood circulation is infected. Less serious symptoms are runny nose, coughing, and constant clearing of the throat. This are signs that more serious symptoms may be seen. These serious symptoms are closing of the windpipe, which leads to trouble swallowing and problems breathing. These can be indicated through wheezing and a blue coloring of the lips and skin. Poor blood circulation leads to a weak pulse, pale skin, and fainting.

A severe case of an allergic reaction, caused by symptoms affecting the respiratory tract and blood circulation, is called anaphylaxis. When symptoms are shown where breathing is impaired and circulation is affected, the person is said to be in anaphylactic shock. Anaphylaxis is where IgE Antibodies are involved, and areas of the body that are not in direct contact with the food get infected and show symptoms. This occurs because no nutrients are circulated throughout the body, causing the widening of blood vessels. The blood vessels widen, and blood pressure decreases, which leads to the loss of consciousness. Those with asthma or an allergy to peanuts, tree nuts, or seafood are at greater risk for anaphylaxis.

Treatment

There are treatments for an allergic reaction. Among the first time the reaction occurs, it is most beneficial to take the person to the emergency room, where proper action may be taken. Other treatments include: epinephrine, antihistamines, and steroids.

Epinephrine

Also known as adenaline, epinephrine is a common medication used to treat allergic reactions. Epinephrine reverses the allergic reaction by improving blood circulation. This is done by tightening blood vessels in order to increase the heart beat and circulation to bodily organs. Epinephrine is produces naturally in the body. It is produced during "flight-or-fight" response. When a person is presented with a dangerous situation, the adrenal gland is triggered to release adrenaline; this gives the person an increased heart rate and more energy to try to fight off the danger being imposed on the individual. Epinephrine is also prescribed by a physician in a form that is self-injectable. This is what is called an epi-pen.

Antihistamines

Antihistamines are also used to treat allergic reactions. Antihistamines block the action of histamines, which causes blood vessels to lose their stiffness and cause itchiness. The most common antihistamine given for food allergies is diphenhydramine, also known as Benedryl. When it comes to dealing with anaphylaxis, antihistamines relieve symptoms; however, they do not completely improve the dangerous symptoms that affect breathing.

Steroids

Steroids are used to calm down the immune system cells that are attacked by the chemicals released during an allergic reaction. This form of treatment in the form of a nasal spray should not be used to treat anaphylaxis, for it only relieves symptoms in the area in which the steroid is in contact. Another reason steroids should not be used to treat anaphylaxis is due to the long amount of time it takes to reduce inflammation and start to work. Steroids can also be taken orally or through injection. By taking a steroid in these manners, every part of the body can be reached and treated, but a long time is usually needed for these to take effect.

Avoidance

In order to avoid an allergic reaction, a strict diet can be followed. It is hard to tell what amount of food can trigger a reaction, so complete avoidance should be followed. In some cases, reactions can be triggered by more than eating foods, and these exposures should try to be avoided. These exposures include: skin contact, inhalation, kissing, participation in sports, blood transfusions, cosmetics, and alcohol.

When avoiding certain foods in order to lessen the risk of reaction, it can be hard to maintain the proper amounts of nutrients. The proper amount of fat and carbohydrates should be maintained. Vitamins and minerals can also be lost and should be maintained in order to live healthily. The chart below shows alternative sources where important nutrients can be obtained when an allergy is present. insert chart