Vicilin is a

legumin Legumin is family of globular proteins obtained from beans, peas, lentils, vetches, hemp (specifically edestin) and other leguminous seeds. Edestin is a biologically active legumin protein that is digestible for human bodies. Garden peas are a c ...

-associated

globulin The globulins are a family of globular proteins that have higher molecular weights than albumins and are insoluble in pure water but dissolve in dilute salt solutions. Some globulins are produced in the liver, while others are made by the immune ...

protein. Vicilin can be described as a storage protein found in

legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock for ...

s such as the

pea The pea is most commonly the small spherical seed or the seed-pod of the flowering plant species ''Pisum sativum''. Each pod contains several peas, which can be green or yellow. Botanically, pea pods are fruit, since they contain seeds and d ...

lentil The lentil (''Lens culinaris'' or ''Lens esculenta'') is an edible legume. It is an annual plant known for its lens-shaped seeds. It is about tall, and the seeds grow in pods, usually with two seeds in each. As a food crop, the largest produ ...

. Vicilin is a protein that protects plants from

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...

and

microorganism A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...

. It has been hypothesized it's an allergen in pea allergy responses.

Function of Vicilin

Vicilin is a globulin present in

s that assists the storage of proteins. Vicilins are 7S globulins. Sucrose binding, antifungal capabilities, and

oxidative stress Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage. Disturbances in the normal r ...

are a few of the globulin's functions. Vicilin peptides produced by digestion using

trypsin Trypsin is an enzyme in the first section of the small intestine that starts the digestion of protein molecules by cutting these long chains of amino acids into smaller pieces. It is a serine protease from the PA clan superfamily, found in the di ...

chymotrypsin Chymotrypsin (, chymotrypsins A and B, alpha-chymar ophth, avazyme, chymar, chymotest, enzeon, quimar, quimotrase, alpha-chymar, alpha-chymotrypsin A, alpha-chymotrypsin) is a digestive enzyme component of pancreatic juice acting in the duodenu ...

offer anti-hypersensitive properties. Vicilin's function was best understood because to the addition of the copper ligand. Vicilin has various significant residues, four of which are involved in copper ion coordination. Vicilin belongs to the cupin family of proteins, therefore metal ligand coordination is common, but Vicilin is the only seed storage protein in this family known to have copper. Due to various enzymatic activities, this inclusion is crucial, because Vicilin's function and mechanism are impacted by these functions.

Vicilin Structure

Vicilin is made up of one alpha subunit, a single

glycerol Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known ...

, and a phosphate ion. The addition of a copper ligand is what helps the structure work out. The

N-terminus The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...

and

C-terminus The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain ( protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is ...

fold into cupin folds to produce conserved beta barrels. Cupin folds cluster in seed storage proteins, and the presence of a metal ligand influences the protein's catalytic action. The C-terminus and N-terminus generate a cupin fold that is symmetrically centered off the axis. This axis is responsible for all copper ligand incorporation. This copper center's structure has four main residues: Cys-338, Tyr-67, His-340, and His-379. The copper ligand is coupled by a

trigonal planar In chemistry, trigonal planar is a molecular geometry model with one atom at the center and three atoms at the corners of an equilateral triangle, called peripheral atoms, all in one plane. In an ideal trigonal planar species, all three ligands ...

structure generated by cysteine's sulfur. The bond formed by a

hydroxyl group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...

attached to Tyr-67 is longer than the previous three. The enzymatic activity is connected to copper binding via histidine residues. These copper ligands are known to perform a catalytic function on proteins. This copper center's structure has four main residues: Cys-338, Tyr-67, His-340, and His-379. The copper ligand is coupled by a

structure generated by cysteine's sulfur. The bond formed by a

Allergen Related Information

Vicilin is a significant allergen found in legumes. The LgE binding proteins found were closely related and belonged to the 7S globulin family of seed storage proteins, which helped identify the

allergen An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms ...

. Cross-reactions with various legumes are common when Pis s 1 and vicilins are combined in other seeds.

Major Vicilin AllergensBarre, Annick et al. “Vicilin Allergens of Peanut and Tree Nuts (walnut, Hazelnut and Cashew Nut) Share Structurally Related IgE-Binding Epitopes.” ''Molecular immunology'' 45.5 (2008): 1231–1240. Web.

# Ana o 1 in cashew nut # Ara h 1 in peanut # Jug r 2 in walnut # Cor a 11 in hazelnut Vicilins have similar amino acid sequences and cross-reactivity happen between vicilin allergens.{{Reflist Plant proteins