ASP53, a thermostable protein from Acacia erioloba seeds that protects target proteins against thermal denaturation

2007 ◽  
Vol 34 (2) ◽  
pp. 139 ◽  
Author(s):  
Linda Mtwisha ◽  
Jill M. Farrant ◽  
Wolf Brandt ◽  
Caswell Hlongwane ◽  
George G. Lindsey
Keyword(s):  
Secondary Structure ◽  
Thermal Denaturation ◽  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Temperature Dependent ◽  
Alcohol Dehydrogenase Activity ◽  
Thermostable Protein ◽  
Three Stages ◽  
Mature Seeds

ASP53, a 53 kDa heat soluble protein, was identified as the most abundant protein in the mature seeds of Acacia erioloba E.Mey. Immunocytochemistry showed that ASP53 was present in the vacuoles and cell walls of the axes and cotyledons of mature seeds and disappeared coincident with loss of desiccation tolerance. The sequence of the ASP53 transcript was determined and found to be homologous to the double cupin domain-containing vicilin class of seed storage proteins. Mature seeds survived heating to 60°C and this may be facilitated by the presence of ASP53. Circular dichroism spectroscopy demonstrated that the protein displayed defined secondary structure, which was maintained even at high temperature. ASP53 was found to inhibit all three stages of protein thermal denaturation. ASP53 decreased the rate of loss of alcohol dehydrogenase activity at 55°C, decreased the rate of temperature-dependent loss of secondary structure of haemoglobin and completely inhibited the temperature-dependent aggregation of egg white protein.

scholarly journals Progressive Aggregation of 16 kDa Gamma-Zein during Seed Maturation in Transgenic Arabidopsis thaliana

2021 ◽  
Vol 22 (23) ◽  
pp. 12671
Author(s):  
Elsa Arcalis ◽  
Davide Mainieri ◽  
Alessandro Vitale ◽  
Eva Stöger ◽  
Emanuela Pedrazzini
Keyword(s):  
Arabidopsis Thaliana ◽  
Storage Proteins ◽  
Transgenic Arabidopsis ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Maize Endosperm ◽  
Mature Embryos ◽  
Er Chaperone ◽  
Reducing Conditions ◽  
Mature Seeds

Prolamins constitute a unique class of seed storage proteins, present only in grasses. In the lumen of the endoplasmic reticulum (ER), prolamins form large, insoluble heteropolymers termed protein bodies (PB). In transgenic Arabidopsis (Arabidopsis thaliana) leaves, the major maize (Zea mays) prolamin, 27 kDa γ-zein (27γz), assembles into insoluble disulfide-linked polymers, as in maize endosperm, forming homotypic PB. The 16 kDa γ-zein (16γz), evolved from 27γz, instead forms disulfide-bonded dispersed electron-dense threads that enlarge the ER lumen without assembling into PB. We have investigated whether the peculiar features of 16γz are also maintained during transgenic seed development. We show that 16γz progressively changes its electron microscopy appearance during transgenic Arabidopsis embryo maturation, from dispersed threads to PB-like, compact structures. In mature seeds, 16γz and 27γz PBs appear very similar. However, when mature embryos are treated with a reducing agent, 27γz is fully solubilized, as expected, whereas 16γz remains largely insoluble also in reducing conditions and drives insolubilization of the ER chaperone BiP. These results indicate that 16γz expressed in the absence of the other zein partners forms aggregates in a storage tissue, strongly supporting the view that 16γz behaves as the unassembled subunit of a large heteropolymer, the PB, and could have evolved successfully only following the emergence of the much more structurally self-sufficient 27γz.

scholarly journals Wheat (Triticum aestivum L.) TaHMW1D Transcript Variants Are Highly Expressed in Response to Heat Stress and in Grains Located in Distal Part of the Spike

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 687
Author(s):  
Chan Seop Ko ◽  
Jin-Baek Kim ◽  
Min Jeong Hong ◽  
Yong Weon Seo
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Temperature Stress ◽  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Two Dimensional Gel Electrophoresis ◽  
Transcript Variants

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.

scholarly journals A Single Seed Protein Extraction Protocol for Characterizing Brassica Seed Storage Proteins

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 107
Author(s):  
Mahmudur Rahman ◽  
Lei Liu ◽  
Bronwyn J. Barkla
Keyword(s):  
Seed Protein ◽  
Storage Proteins ◽  
Protein Extraction ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Protein Yield ◽  
Tissue Type ◽  
Single Seed ◽  
Material Optimization ◽  
Hazardous Chemical

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.

Seed storage proteins in developing somatic embryos of alfalfa: defects in accumulation compared to zygotic embryos

1994 ◽  
Vol 45 (6) ◽  
pp. 699-708 ◽  
Author(s):  
Joan E. Krochko ◽  
David J. Bantroch ◽  
John S. Greenwood ◽  
J. Derek Bewley
Keyword(s):  
Somatic Embryos ◽  
Storage Proteins ◽  
Seed Storage ◽  
Seed Storage Proteins ◽  
Zygotic Embryos

Molecular cloning, sequencing, and chromosome mapping of a 1A-encoded ω-type prolamin sequence from wheat

Genome ◽  
2002 ◽  
Vol 45 (4) ◽  
pp. 661-669 ◽  
Author(s):  
Ali Masoudi-Nejad ◽  
Shuhei Nasuda ◽  
Akira Kawabe ◽  
Takashi R Endo
Keyword(s):  
Storage Proteins ◽  
Protein Structures ◽  
Seed Storage ◽  
Chromosome Mapping ◽  
Seed Storage Proteins ◽  
Gene Families ◽  
Start Codon ◽  
Pcr Analysis ◽  
Bread Making ◽  
Deletion Lines

Gliadins are the most abundant component of the seed storage proteins in cereals and, in combination with glutenins, are important for the bread-making quality of wheat. They are divided into four subfamilies, the α-, β-, γ-, and ω-gliadins, depending on their electrophoresis pattern, chromosomal location, and DNA and protein structures. Using a PCR-based strategy we isolated and sequenced an ω-gliadin sequence. We also determined the chromosomal subarm location of this sequence using wheat aneuploids and deletion lines. The gene is 1858 bp long and contains a coding sequence 1248 bp in length. Like all other gliadin gene families characterized in cereals, the ω-gliadin gene described here had characteristic features including two repeated sequences 300 bp upstream of the start codon. At the DNA level, the gene had a high degree of similarity to the ω-secalin and C-hordein genes of rye and barley, but exhibited much less homology to the α- and β-gliadin gene families. In terms of the deduced amino acid sequence, this gene has about 80 and 70% similarity to the ω-secalin and C-hordein genes, respectively, and possesses all the features reported for other gliadin gene families. The ω-gliadin gene has about 30 repeats of the core consensus sequences PQQPX and XQQPQQX, twice as many as other gliadin gene families. Southern blotting and PCR analysis with aneuploid and deletion lines for the short arm of chromosome 1A showed that the ω-gliadin was located on the distal 25% of the short arm of chromosome 1A. By comparison of PCR and A-PAGE profiles for deletion stocks, its genomic location must be at a different locus from gli-A1a in 'Chinese Spring'.Key words: glutenin, omega gliadin, storage protein, Triticum aestivum, secalin.

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