Prolamin


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Related to Prolamin: glutelin

prolamin

[prō′lam·ən]
(biochemistry)
Any of the simple proteins, such as zein, found in plants; soluble in strong alcohol, insoluble in absolute alcohol and water.

Prolamin

 

a simple reserve protein found only in the seeds of cereals. Prolamins include gliadin, found in wheat and rye, zein, found in corn, hordein, found in barley, avenin, found in oats, oryzin, found in rice, and kaffirin, found in sorghum. Prolamins are soluble in 60–80 percent aqueous ethyl alcohol. They contain radicals of glutamic acid (over 40 percent) and proline (about 15 percent) but very little lysine, which accounts for the biological inferiority of the reserve proteins of grain crops.

Prolamins are heterogeneous. It is possible to divide them by means of chromatography and electrophoresis into components that are closely related in amino-acid composition but that differ in molecular weight and electrical charge; for example, the prolamin of wheat divides into 15 to 30 components with molecular weights that range from 31,000 to 78,000. The majority of components consist of a single polypeptide chain. Some components are capable of polymerizing through disulfide bonds and becoming parts of glutelins. The componential composition of gliadin is determined genetically and is an indicator of wheat variety. In wheat grains, gliadin and glutenin form gluten; the bread-baking quality of wheat depends on the content and physical properties of gluten.

A. B. VAKAR

References in periodicals archive ?
Delivery of prolamins to the protein storage vacuole in maize aleurone cells.
This is in contrast to corn, for example, in which an increase in crude protein is accompanied by increased levels of prolamin fraction, leading to reduced nutritional quality, because this fraction has lower levels of essential amino acids.
Low-tannin cultivar Fermenta Albumin Globulin Prolamin Glutelin Albumin tion time (h) 0 11.
Cumulative and interaction effects of prolamin allelic variation and 1BL/1RS translocation on flour quality in bread wheat.
A densitometer scan of the stained gel containing equal volume of proteins revealed the amount of the 14-kDa prolamin was 60% lower in the two mutants compared with the parent Calrose 76.
mutant having a low content of glutelin and a high content of prolamin.
We also checked for the presence of prolamins in embryos by incubating thin sections of rice caryopses with prolamin antibodies and protein A-gold.
globulins and prolamins, which are synthesized in the Golgi apparatus and the endoplasmic reticulum and accumulate as protein bodies (Marty, 1999).
Biochemically, during the storage period it is prudent to state that the main alterations highlighted in the literature are the hydrolysis of prolamins and hemicellulose.
6%, respectively), which strongly indicated that most of the soluble protein fractions in DDGS had been removed during processing and resulted in a very insoluble, ruminally undegradable protein that contained mostly prolamins and glutelins (Clark et al.