scholarly journals Biochemical Aspects of a Serine Protease fromCaesalpinia echinataLam. (Brazilwood) Seeds: A Potential Tool to Access the Mobilization of Seed Storage Proteins

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Priscila Praxedes-Garcia ◽  
Ilana Cruz-Silva ◽  
Andrezza Justino Gozzo ◽  
Viviane Abreu Nunes ◽  
Ricardo José Torquato ◽  
...  

Several proteins have been isolated from seeds of leguminous, but this is the first report that a protease was obtained from seeds ofCaesalpinia echinataLam., a tree belonging to the Fabaceae family. This enzyme was purified to homogeneity by hydrophobic interaction and anion exchange chromatographies and gel filtration. This 61-kDa serine protease (CeSP) hydrolyses H-D-prolyl-L-phenylalanyl-L-arginine-p-nitroanilide (Km55.7 μM) in an optimum pH of 7.1, and this activity is effectively retained until50∘C. CeSP remained stable in the presence of kosmotropic anions (PO4 3−,SO4 2−, andCH3COO−) or chaotropic cations (K+and Na+). It is strongly inhibited by TLCK, a serine protease inhibitor, but not by E-64, EDTA or pepstatin A. The characteristics of the purified enzyme allowed us to classify it as a serine protease. The role of CeSP in the seeds cannot be assigned yet but is possible to infer that it is involved in the mobilization of seed storage proteins.

2015 ◽  
Vol 4 ◽  
Author(s):  
Ederlan S. Ferreira ◽  
Ana Lucia S. Amaral ◽  
Aureluce Demonte ◽  
Cleslei F. Zanelli ◽  
Jessica Capraro ◽  
...  

AbstractThe role of seed proteins, especially soyabean 7S globulins, in controlling dyslipidaemia is widely acknowledged. Amino acid sequence homology among the proteins of this family could reflect similar biological functions in other species. The aim of the present study was to unveil a hypolipidaemic effect of the 7S globulins from cowpeas (7S-C) and adzuki beans (7S-A), administered orally to rats fed a hypercholesterolaemic (HC; high cholesterol and TAG) diet for 28 d. A total of forty-five rats were divided into five groups (nine rats per group): (1) standard (STD) diet; (2) HC diet; (3) HC diet + 7S-C (300 mg/kg per d); (4) HC diet + 7S-A (300 mg/kg per d); and (5) HC diet + simvastatin (SVT; 50 mg/kg per d), as a control. Significant decreases in food intake and final body weight of rats receiving HC + 7S-C and HC + 7S-A diets compared with groups fed the HC and STD diets were observed. Significant decreases in serum total and non-HDL-cholesterol of 7S-C, 7S-A and SVT groups were also observed. HDL-cholesterol levels increased in the 7S-C, 7S-A and SVT groups, while hepatic cholesterol and TAG concentrations were significantly lower than in the HC diet group for the 7S-C-supplemented group only. Faecal excretions of fat and cholesterol in HC diet groups were considerably higher in animals consuming the 7S globulins. The results show that cowpea and adzuki bean 7S globulins promote cholesterol-decreasing effects in hypercholesterolaemic rats even at low dosages, as already observed for other legume seed storage proteins of this family. This main effect is discussed in relation to the possible mechanisms of action.


1990 ◽  
Vol 17 (3) ◽  
pp. 355 ◽  
Author(s):  
D Spencer ◽  
WG Rerie ◽  
PJ Randall ◽  
TJV Higgins

In this review the role of sulfur in regulating the expression of genes for pea seed storage proteins in both peas and transgenic tobacco is discussed. The levels of the sulfur-containing proteins, legumin and pea albumin 1 (PA1), are reduced in the seeds of peas grown under mild sulfur nutrient stress. In contrast, the levels of sulfur-poor proteins such as pea lectin and vicilin are either unaffected or increased slightly under the same conditions. The levels of all the proteins are a direct reflection of the levels of their respective mRNAs. The reduced levels of legumin and PA1 mRNAs under sulfur stress is known to be due largely to increased mRNA turnover rather than decreased transcription. The advent of gene transfer procedures for plants has allowed re-examination of the mechanism of regulation of mRNA stability under conditions of sulfur stress. A pea albumin 1 gene was engineered for leaf expression and transferred to tobacco and the transgenic plants were grown on normal and low levels of sulfur. Sulfur stress reduces total leaf protein in tobacco by about 20% and there are minor qualitative changes in the total protein profile. In contrast, PA1 levels are reduced by over 90% compared with the controls when the transgenic tobaccos are grown under sulfur stress. Thus, it is clear that sequences responsible for recognising the sulfur status have been included in the transgene. A number of gene constructs have been designed to test where the sulfur-responsive sequences are located in the PA1 gene and some of the preliminary findings are reported.


1995 ◽  
Vol 5 (4) ◽  
pp. 209-218 ◽  
Author(s):  
Karl A. Wilson ◽  
Mary Russell ◽  
John F. Quackenbush ◽  
Anna L. Tan-Wilson

AbstractThere is a carboxypeptidase in mung bean seeds that is localized in the protein bodies, the same vacuoles in which seed storage proteins are sequestered. This carboxypeptidase, called carboxypeptidase I (or Cpase I) has been purified by a series of ion-exchange and gel filtration columns. The pure enzyme consists of a single polypeptide chain with a MW of 41700 by SDS-PAGE or 42000 by size-exclusion HPLC. It has a pl of 4.36 and is a serine carboxypeptidase as shown by its inactivation by phenylmethylsulfonyl fluoride, and its resistance to other proteolytic inhibitory reagents. A survey of its activity with Cbz-dipeptides shows preference for C-terminal amino acids that are large, hydrophobic residues, and a small aliphatic amino acid such as alanine, but not glycine, at the penultimate amino acid residue. Cpase I can convert a trypsin inhibitor of the mung bean to its proteolytic intermediate lacking four amino acid residues at its C-terminus. This proteolytic intermediate is detected in the mung bean cotyledons during early growth. Levels of both the activity and immunological cross-reacting forms of this enzyme start high and decrease during early growth.


2001 ◽  
Vol 13 (1) ◽  
pp. 33-40 ◽  
Author(s):  
SANDRA M. T. BAÚ ◽  
PAULO MAZZAFERA ◽  
LUIZ G. SANTORO

It has been reported that Coffea arabica seeds contain as the main reserve protein, a legumin-like protein, constituted of two subunits, alpha and beta, of approximately 35 and 20 kDa. In this work the seed proteins of several coffee species and varieties were investigated by SDS-PAGE and gel filtration. No differences were observed in the electrophoretic profiles among varieties of C. arabica, however, marked differences were observed among species, or even among individuals of some species. In general, the molecular weight of the subunits alpha and beta accounted for a monomer of 48 to 62 kDa. However, native molecular weight obtained by gel filtration showed that for most of the species there is association of 6 of such proteins, in a hexamer. The most marked difference was observed for C. canephora and C. racemosa. The former clearly showing isoforms of the subunits, and the later showing absence of the beta subunit. The influence of proteases in this observations is discussed.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 687
Author(s):  
Chan Seop Ko ◽  
Jin-Baek Kim ◽  
Min Jeong Hong ◽  
Yong Weon Seo

High-temperature stress during the grain filling stage has a deleterious effect on grain yield and end-use quality. Plants undergo various transcriptional events of protein complexity as defensive responses to various stressors. The “Keumgang” wheat cultivar was subjected to high-temperature stress for 6 and 10 days beginning 9 days after anthesis, then two-dimensional gel electrophoresis (2DE) and peptide analyses were performed. Spots showing decreased contents in stressed plants were shown to have strong similarities with a high-molecular glutenin gene, TraesCS1D02G317301 (TaHMW1D). QRT-PCR results confirmed that TaHMW1D was expressed in its full form and in the form of four different transcript variants. These events always occurred between repetitive regions at specific deletion sites (5′-CAA (Glutamine) GG/TG (Glycine) or (Valine)-3′, 5′-GGG (Glycine) CAA (Glutamine) -3′) in an exonic region. Heat stress led to a significant increase in the expression of the transcript variants. This was most evident in the distal parts of the spike. Considering the importance of high-molecular weight glutenin subunits of seed storage proteins, stressed plants might choose shorter polypeptides while retaining glutenin function, thus maintaining the expression of glutenin motifs and conserved sites.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 107
Author(s):  
Mahmudur Rahman ◽  
Lei Liu ◽  
Bronwyn J. Barkla

Rapeseed oil-extracted expeller cake mostly contains protein. Various approaches have been used to isolate, detect and measure proteins in rapeseeds, with a particular focus on seed storage proteins (SSPs). To maximize the protein yield and minimize hazardous chemical use, isolation costs and the loss of seed material, optimization of the extraction method is pivotal. For some studies, it is also necessary to minimize or avoid seed-to-seed cross-contamination for phenotyping and single-tissue type analysis to know the exact amount of any bioactive component in a single seed, rather than a mixture of multiple seeds. However, a simple and robust method for single rapeseed seed protein extraction (SRPE) is unavailable. To establish a strategy for optimizing SRPE for downstream gel-based protein analysis, yielding the highest amount of SSPs in the most economical and rapid way, a variety of different approaches were tested, including variations to the seed pulverization steps, changes to the compositions of solvents and reagents and adjustments to the protein recovery steps. Following SRPE, 1D-SDS-PAGE was used to assess the quality and amount of proteins extracted. A standardized SRPE procedure was developed and then tested for yield and reproducibility. The highest protein yield and quality were obtained using a ball grinder with stainless steel beads in Safe-Lock microcentrifuge tubes with methanol as the solvent, providing a highly efficient, economic and effective method. The usefulness of this SRPE was validated by applying the procedure to extract protein from different Brassica oilseeds and for screening an ethyl methane sulfonate (EMS) mutant population of Brassica rapa R-0-18. The outcomes provide useful methodology for identifying and characterizing the SSPs in the SRPE.


1994 ◽  
Vol 45 (6) ◽  
pp. 699-708 ◽  
Author(s):  
Joan E. Krochko ◽  
David J. Bantroch ◽  
John S. Greenwood ◽  
J. Derek Bewley

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