scholarly journals The purification and characterization of a third storage protein (convicilin) from the seeds of pea (Pisum sativum L.)

1980 ◽  
Vol 191 (2) ◽  
pp. 509-516 ◽  
Author(s):  
R R Croy ◽  
J A Gatehouse ◽  
M Tyler ◽  
D Boulter

A third storage protein, distinct from legumin and vicilin, has been purified from the seeds of pea (Pisum sativum L.). This protein has been named ‘convicilin’ and is present in protein bodies isolated from pea seeds. Convicilin has a subunit mol.wt. of 71 000 and a mol.wt. in its native form of 290 000. Convicilin is antigenically dissimilar to legumin, but gives a reaction of identity with vicilin when tested against antibodies raised against both proteins. However, convicilin contains no vicilin subunits and may be clearly separated from vicilin by non-dissociating techniques. Unlike vicilin, convicilin does not interact with concanavalin A, and contains insignificant amounts of carbohydrates. Limited heterogeneity, as shown by isoelectric focusing, N-terminal analysis, and CNBr cleavage, is present in convicilin isolated from a single pea variety; genetic variation of the protein between pea lines has also been observed.

1985 ◽  
Vol 225 (1) ◽  
pp. 239-247 ◽  
Author(s):  
J A Gatehouse ◽  
J Gilroy ◽  
M S Hoque ◽  
R R D Croy

The seeds of pea (Pisum sativum L.) contain several proteins in the albumin solubility fraction that are significant components of total cotyledonary protein (5-10%) and are accumulated in developing seeds concurrently with storage-protein synthesis. One of these proteins, of low Mr and designated ‘Psa LA’, has been purified, characterized and sequenced. Psa LA has an Mr of 11000 and contains polypeptides of Mr 6000, suggesting that the protein molecules are dimeric. The amino acid sequence contains 54 residues, with a high content (10/54) of asparagine/aspartate. It has no inhibitory action towards trypsin or chymotrypsin, and is distinct from the inhibitors of those enzymes found in pea seeds, nor does it inhibit hog pancreatic alpha-amylase. The protein contains no methionine, but significant amounts of cysteine (four residues per polypeptide), suggesting a possible role as a sulphur storage protein. However, its sequence is not homologous with low-Mr (2S) storage proteins from castor bean (Ricinus communis) or rape (Brassica napus). Psa LA therefore represents a new type of low-Mr seed protein.


Author(s):  
Vanessa Vernoud ◽  
Ludivine Lebeigle ◽  
Jocelyn Munier ◽  
Julie Marais ◽  
Myriam Sanchez ◽  
...  

Abstract The use of pulses as ingredients for the production of food products rich in plant proteins is increasing. However, protein fractions prepared from pea or other pulses contain significant amounts of saponins, glycosylated triterpenes which can impart an undesirable bitter taste when used as an ingredient in foodstuffs. In this paper, we describe the identification and characterization of a gene involved in saponin biosynthesis during pea seed development, by screening mutants obtained from two Pisum sativum TILLING (Targeting Induced Local Lesions in Genomes) populations in two different genetic backgrounds. The mutations studied are located in a gene designated PsBAS1 (β-amyrin synthase1) which is highly expressed in maturing pea seeds and which encodes a protein previously shown to correspond to an active β-amyrin synthase. The first allele is a nonsense mutation, while the second mutation is located in a splice site and gives rise to a mis-spliced transcript encoding a truncated, non-functional protein. The homozygous mutant seeds accumulated virtually no saponin without affecting seed nutritional or physiological quality. Interestingly, BAS1 appears to control saponin accumulation in all other tissues of the plant examined. These lines represent a first step in the development of pea varieties lacking bitterness off-flavours in their seeds. Our work also shows that TILLING populations in different genetic backgrounds represent valuable genetic resources for both crop improvement and functional genomics.


1997 ◽  
Vol 77 (1) ◽  
pp. 101-103 ◽  
Author(s):  
T. D. Warkentin ◽  
A. G. Sloan ◽  
S. T. Ali-Khan

Field pea seeds from 10 cultivars grown at two locations in Manitoba in 1986 and 1987 were analyzed for proximate and mineral profiles. Cultivars differed significantly in their level of total protein, crude fat, ADF, and all minerals tested. However, differences were not extremely large and were comparable to European reports. Location-year also had a significant effect on the levels of total protein, ADF, and all minerals tested. In most cases, the warmest location-year produced relatively higher levels of minerals, ash, and total protein, and lower seed yield than the coolest location-year. Key words: Field pea, Pisum sativum L., mineral


Heredity ◽  
1984 ◽  
Vol 53 (1) ◽  
pp. 185-191 ◽  
Author(s):  
Sayed H Mahmoud ◽  
John A Gatehouse

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