Pentadin, a
sweet-tasting protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
, was discovered and isolated in 1989 from the fruit of
oubli
''Pentadiplandra brazzeana'', also known as oubli, is an evergreen shrub or liana that is the only species assigned to the genus ''Pentadiplandra'', and has been placed in a family of its own called Pentadiplandraceae. It produces large red berri ...
(''
Pentadiplandra brazzeana'' ), a climbing shrub growing in some tropical countries of
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...
.
''
Pentadiplandra brazzeana''
berry
A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit although many pips or seeds may be present. Common examples of berries in the cul ...
consists of a red
pericarp
Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits.
Fruitlike structures may develop directly from the seed itself rather th ...
with seeds and flesh containing sweet tasting proteins that can be
extract
An extract (essence) is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures or absolutes or dried and powdered.
The aromatic principles of ma ...
ed for production of a
sugar substitute
A sugar substitute or artificial sweetener, is a food additive that provides a sweetness like that of sugar while containing significantly less food energy than sugar-based sweeteners, making it a zero-calorie () or low-calorie sweetener. Arti ...
.
History
Pentadin (discovered in 1989) and
brazzein
Brazzein is a sweet-tasting protein that occurs naturally in oubli (''Pentadiplandra brazzeana''), a fruit native to the Atlantic coastal areas of Central Africa. Brazzein was first isolated in 1994 by scientists at the University of Wisconsin� ...
(discovered in 1994) are the two names proposed for the sweet-tasting protein(s) isolated via two different methods from the same African fruit, ''
Pentadiplandra brazzeana''. The corresponding author of both these publications has later opined that pentadin and brazzein are two different names for the same protein. Even though pentadin is the earlier proposed name, brazzein is the more commonly used name after more extensive characterisation of the sweet protein.
Description

Sweet tasting proteins have been known to exist for many years and indigenous people have been known to use these proteins as a way to add sweetness to their foods without the use of other sweetening agents, such as sucrose.
The sweetness of pentadin/brazzein has been estimated to be about 500 times more than sucrose, on a weight basis.
This sweet tasting protein is known to resemble
monellin
Monellin, a sweet protein, was discovered in 1969 in the fruit of the West African shrub known as serendipity berry ('' Dioscoreophyllum cumminsii''); it was first reported as a carbohydrate.GE Inglett, JF May. Serendipity berries - Source of a ...
on a sweetness basis and is higher than
thaumatin
Thaumatin (also known as talin) is a low-calorie sweetener and taste modifier. The protein is often used primarily for its flavor-modifying properties and not exclusively as a sweetener.
The thaumatins were first found as a mixture of protein ...
.

There are five sweet-tasting proteins -
thaumatin
Thaumatin (also known as talin) is a low-calorie sweetener and taste modifier. The protein is often used primarily for its flavor-modifying properties and not exclusively as a sweetener.
The thaumatins were first found as a mixture of protein ...
,
monellin
Monellin, a sweet protein, was discovered in 1969 in the fruit of the West African shrub known as serendipity berry ('' Dioscoreophyllum cumminsii''); it was first reported as a carbohydrate.GE Inglett, JF May. Serendipity berries - Source of a ...
,
mabinlin
Mabinlins are sweet, sweet-tasting proteins extracted from the seed of mabinlang (''Capparis masaikai Levl.''), a plant growing in Yunnan province of China. There are four homologues. Mabinlin-2 was first isolated in 1983 and characterised i ...
,
brazzein
Brazzein is a sweet-tasting protein that occurs naturally in oubli (''Pentadiplandra brazzeana''), a fruit native to the Atlantic coastal areas of Central Africa. Brazzein was first isolated in 1994 by scientists at the University of Wisconsin� ...
/pentadin, and
curculin
Curculin or neoculin is a sweet protein complex that was discovered and isolated in 1990 from the fruit of '' Curculigo latifolia'' ( Hypoxidaceae). Like miraculin, curculin exhibits taste-modifying activity; however, unlike miraculin, it also ...
- all of which are isolated from plants in tropical forests. These proteins show no similarities in a structural or homologous sequence aspect. All of these sweet tasting proteins have different molecular lengths, with no sequence homology and little to none structural homology. Efforts to identify structural similarities among sweet tasting proteins included using the 3D structures and DALI to find similarities. However only a vague resemblance was found for the three proteins tested, monellin, thaumatin, and brazzein.
Uses
The five sweet-tasting proteins are possibly useful to manufacture a low-calorie sweetener to replace certain sugars.
See also
*
Brazzein
Brazzein is a sweet-tasting protein that occurs naturally in oubli (''Pentadiplandra brazzeana''), a fruit native to the Atlantic coastal areas of Central Africa. Brazzein was first isolated in 1994 by scientists at the University of Wisconsin� ...
*
Mabinlin
Mabinlins are sweet, sweet-tasting proteins extracted from the seed of mabinlang (''Capparis masaikai Levl.''), a plant growing in Yunnan province of China. There are four homologues. Mabinlin-2 was first isolated in 1983 and characterised i ...
*
Monellin
Monellin, a sweet protein, was discovered in 1969 in the fruit of the West African shrub known as serendipity berry ('' Dioscoreophyllum cumminsii''); it was first reported as a carbohydrate.GE Inglett, JF May. Serendipity berries - Source of a ...
*
Thaumatin
Thaumatin (also known as talin) is a low-calorie sweetener and taste modifier. The protein is often used primarily for its flavor-modifying properties and not exclusively as a sweetener.
The thaumatins were first found as a mixture of protein ...
*
Miraculin
Miraculin is a taste modifier, a glycoprotein extracted from the fruit of '' Synsepalum dulcificum''. The berry, also known as the miracle fruit, was documented by explorer Chevalier des Marchais, who searched for many different fruits during ...
*
Curculin
Curculin or neoculin is a sweet protein complex that was discovered and isolated in 1990 from the fruit of '' Curculigo latifolia'' ( Hypoxidaceae). Like miraculin, curculin exhibits taste-modifying activity; however, unlike miraculin, it also ...
*
Lysosyme
References
{{Reflist
Sugar substitutes
Proteins