MyMedR

Displaying publications 21 - 30 of 30 in total

Abstract:

Sort:

A comparative study of physicochemical characteristics and functionalities of pinto bean protein isolate (PBPI) against the soybean protein isolate (SPI) after the extraction optimisation

Tan ES, Ying-Yuan N, Gan CY

Food Chem, 2014;152:447-55.
PMID: 24444960 DOI: 10.1016/j.foodchem.2013.12.008

Optimisation of protein extraction yield from pinto bean was investigated using response surface methodology. The maximum protein yield of 54.8 mg/g was obtained with the optimal conditions of: temperature=25 °C, time=1 h and buffer-to-sample ratio=20 ml/g. PBPI was found to obtain high amount of essential amino acids such as leucine, lysine, and phenylalanine compared to SPI. The predominant proteins of PBPI were vicilin and phytohemagglutinins whereas the predominant proteins of SPI were glycinin and conglycinins. Significantly higher emulsifying capacity was found in PBPI (84.8%) compared to SPI (61.9%). Different isoelectric points were found in both PBPI (4.0-5.5) and SPI (4.0-5.0). Also, it was found that PBPI obtained a much higher denaturation temperature of 110.2 °C compared to SPI (92.5 °C). Other properties such as structural information, gelling capacity, water- and oil-holding capacities, emulsion stability as well as digestibility were also reported.

Matched MeSH terms: Plant Proteins/isolation & purification
Proteome analysis of abundant proteins extracted from the leaf of Gynura procumbens (Lour.) Merr

Hew CS, Gam LH

Appl Biochem Biotechnol, 2011 Dec;165(7-8):1577-86.
PMID: 21938418 DOI: 10.1007/s12010-011-9377-x

Gynura procumbens (Lour.) Merr. is a traditionally used medicinal plant to decrease cholesterol level, reduce high blood pressure, control diabetics, and for treatment of cancer. In our present study, a proteomic approach was applied to study the proteome of the plant that had never analyzed before. We have identified 92 abundantly expressed proteins from the leaves of G. procumbens (Lour.) Merr. Amongst the identified proteins was miraculin, a taste-masking agent with high commercial value. Miraculin made up ∼0.1% of the total protein extracted; the finding of miraculin gave a great commercial value to G. procumbens (Lour.) Merr. as miraculin's natural source is limited while the production of recombinant miraculin faced challenges of not being able to exhibit the taste-masking effect as in the natural miraculin. We believe the discovery of miraculin in G. procumbens (Lour.) Merr., provides commercial feasibility of miraculin in view of the availability of G. procumbens (Lour.) Merr. that grow wildly and easily in tropical climate.

Matched MeSH terms: Plant Proteins/isolation & purification
Method development for analysis of proteins extracted from the leaves of Orthosiphon aristatus

Koay SY, Gam LH

J Chromatogr B Analyt Technol Biomed Life Sci, 2011 Jul 15;879(22):2179-83.
PMID: 21689998 DOI: 10.1016/j.jchromb.2011.05.041

Orthosiphon aristatus is a traditionally used medicinal plant. In order to study the proteome of the plant, we have developed a simple plant protein extraction method by direct extraction of protein using a modified 2D-gel compatible tris-sucrose buffer followed by a double TCA-acetone precipitation. This method omitted the use of toxic phenol which is widely used in the studies of plants proteins. Moreover, it shortens the lengthy extraction procedure of phenol extraction and back-extraction method and therefore reduced the extraction time (by 2h) while increased in protein yields (by 50%). Comparison of the 2D-gel images of the two extracts revealed that >60 extra protein spots were detected in the extract of our current method. The method was applied on the leaves of O. aristatus collected from six geographical areas in Malaysia. The correlation coefficient of each replicate gels from the six areas ranged from 0.70 to 0.90 indicating good reproducibility of the method.

Matched MeSH terms: Plant Proteins/isolation & purification
Purification and characterization of 31-kDa palm pollen glycoprotein (Ela g Bd 31 K), which is recognized by IgE from palm pollinosis patients

Kimura Y, Maeda M, Kimupa M, Lai OM, Tan SH, Hon SM, et al.

Biosci Biotechnol Biochem, 2002 Apr;66(4):820-7.
PMID: 12036055

A basic glycoprotein, which was recognized by IgE from oil palm pollinosis patients, has been purified from oil palm pollen (Elaeis guineensis Jacq.), which is a strong allergen and causes severe pollinosis in Malaysia and Singapore. Soluble proteins were extracted from defatted palm pollen with both Tris-HCl buffer (pH 7.8) and Na-acetate buffer (pH 4.0). The allergenic glycoprotein was purified from the total extract to homogeneity with 0.4% yield by a combination of DEAE- and CM-cellulose, SP-HPLC, and gel filtration. The purified oil palm pollen glycoprotein with molecular mass of 31 kDa was recognized by the beta1-2 xylose specific antibody, suggesting this basic glycoprotein bears plant complex type N-glycan(s). The palm pollen basic glycoprotein, designated Ela g Bd 31 K, was recognized by IgE of palm pollinosis patients, suggesting Ela g Bd 31 K should be one of the palm pollen allergens. The preliminary structural analysis of N-glycans linked to glycoproteins of palm pollens showed that the antigenic N-glycans having alpha1-3 fucose and alpha1-2 xylose residues (GlcNAc(2 to approximately 0)Man3Xyl1Fuc(1 to approximately 0)GlcNAc2) actually occur on the palm pollen glycoproteins, in addition to the high-mannose type structures (Man(9 to approximately 5)GlcNAc2).

Matched MeSH terms: Plant Proteins/isolation & purification
High yield production of sugars from deproteinated palm kernel cake under microwave irradiation via dilute sulfuric acid hydrolysis

Fan SP, Jiang LQ, Chia CH, Fang Z, Zakaria S, Chee KL

Bioresour Technol, 2014 Feb;153:69-78.
PMID: 24342947 DOI: 10.1016/j.biortech.2013.11.055

Recent years, great interest has been devoted to the conversion of biomass-derived carbohydrate into sugars, such as glucose, mannose and fructose. These are important versatile intermediate products that are easily processed into high value-added biofuels. In this work, microwave-assisted dilute sulfuric acid hydrolysis of deproteinated palm kernel cake (DPKC) was systematically studied using Response Surface Methodology. The highest mannose yield (92.11%) was achieved at the optimized condition of 148°C, 0.75N H2SO4, 10min 31s and substrate to solvent (SS) ratio (w/v) of 1:49.69. Besides that, total fermentable sugars yield (77.11%), was obtained at 170°C, 0.181N H2SO4, 6min 6s and SS ratio (w/v) of 1:40. Ridge analysis was employed to further verify the optimum conditions. Thus, this work provides fundamental data of the practical use of DPKC as low cost, high yield and environmental-friendly material for the production of mannose and other sugars.

Matched MeSH terms: Plant Proteins/isolation & purification*
The manufacture of gloves from natural rubber latex

Yip E, Cacioli P

J Allergy Clin Immunol, 2002 Aug;110(2 Suppl):S3-14.
PMID: 12170237 DOI: 10.1067/mai.2002.124499

Gloves that will provide a barrier of protection from infectious organisms are an essential feature of medical practice for the protection of both patients and medical personnel. Natural rubber latex has consistently been the most satisfactory raw material for the manufacture of gloves. Certain latex proteins, carried over into the finished product by inadequate manufacturing processes, may pose a risk of provoking allergic reactions in some patients and medical workers. As with any allergy, the risk depends on the route of exposure and dose. Hence, the method of manufacture, including the means used to coat gloves to make donning easy, can influence the eventual exposure of sensitive people to latex allergens. In this article, we describe the several processes in use and their effects on latex protein content.

Matched MeSH terms: Plant Proteins/isolation & purification
Cloning, expression, and characterization of recombinant Hev b 3, a Hevea brasiliensis protein associated with latex allergy in patients with spina bifida

Wagner B, Krebitz M, Buck D, Niggemann B, Yeang HY, Han KH, et al.

J Allergy Clin Immunol, 1999 Nov;104(5):1084-92.
PMID: 10550757

BACKGROUND: Two natural rubber latex proteins, Hev b 1 and Hev b 3, have been described in spina bifida (SB)-associated latex allergy.
OBJECTIVE: The aim of this study was to clone and express Hev b 3 and to obtain the immunologic active and soluble recombinant allergen for diagnosis of SB-associated latex allergy.
METHODS: A complementary DNA (cDNA) coding for Hev b 3 was amplified from RNA of fresh latex collected from Malaysian rubber trees (Hevea brasiliensis). PCR primers were designed according to sequences of internal peptide fragments of natural (n) Hev b 3. The 5'-end sequence was obtained by specific amplification of cDNA ends. The recombinant (r) Hev b 3 was produced in Escherichia coli as a 6xHis tagged protein. Immunoblotting and inhibition assays were performed to characterize the recombinant allergen.
RESULTS: An Hev b 3 cDNA clone of 922 bp encoding a protein of 204 amino acid residues corresponding to a molecular weight of 22.3 kd was obtained. In immunoblots 29/35, latex-allergic patients with SB revealed IgE binding to rHev b 3, as did 4 of 15 of the latex-sensitized group. The presence of all IgE epitopes on rHev b 3 was shown by its ability to abolish all IgE binding to nHev b 3. Hev b 3 is related to Hev b 1 by a sequence identity of 47%. Cross-reactivity between these 2 latex allergens was illustrated by the large extent of inhibition of IgE binding to nHev b 1 by rHev b 3.
CONCLUSION: rHev b 3 constitutes a suitable in vitro reagent for the diagnosis of latex allergy in patients with SB. The determination of the full sequence of Hev b 3 and the production of the recombinant allergen will allow the epitope mapping and improve diagnostic reagents for latex allergy.

Matched MeSH terms: Plant Proteins/isolation & purification
Optimization of hexametaphosphate-assisted extraction and functional characterization of palm kernel cake protein

Chee KL, Ayob MK

Food Sci Technol Int, 2013 Apr;19(2):109-22.
PMID: 23520324 DOI: 10.1177/1082013212442185

Response surface methodology was applied to study the optimization of palm kernel cake protein (PKCP) hexametaphosphate-assisted extraction. The optimum PKCP yield (28.37%) when extracted using 1.50% sodium hexametaphosphate (SHMP) of pH 10, at 50 °C, and the 1:70 (w/v) ratio of cake-to-solvent was significantly (P

Matched MeSH terms: Plant Proteins/isolation & purification*
Neoculin as a new taste-modifying protein occurring in the fruit of Curculigo latifolia

Shirasuka Y, Nakajima K, Asakura T, Yamashita H, Yamamoto A, Hata S, et al.

Biosci Biotechnol Biochem, 2004 Jun;68(6):1403-7.
PMID: 15215616

A unique taste-modifying activity that converts the sense of sourness to the sense of sweetness occurs in the fruit of the plant Curculigo latifolia, intrinsic to West Malaysia. The active component, known as curculin, is a protein consisting of two identical subunits. We have found a new taste-modifying protein, named neoculin, of the same origin. Both chemical analysis and cDNA cloning characterized neoculin as a heterodimeric protein consisting of an acidic, glycosylated subunit of 113 amino acid residues and a basic subunit that is the monomeric curculin itself.

Matched MeSH terms: Plant Proteins/isolation & purification*
Precipitation of Hevea brasiliensis latex proteins with trichloroacetic acid and phosphotungstic acid in preparation for the Lowry protein assay

Yeang HY, Yusof F, Abdullah L

Anal Biochem, 1995 Mar 20;226(1):35-43.
PMID: 7785777

Many proteins derived from the latex of Hevea brasiliensis that remain soluble in trichloroacetic acid (TCA) can be precipitated by phosphotungstic acid (PTA). A combination of 5% TCA and 0.2% PTA precipitates a wide range of proteins effectively even when they are present in low concentrations (below 1 microgram ml-1). In addition to its protein purification function, acid precipitation also increases the sensitivity of the subsequent protein assay by allowing the test sample to be concentrated. Another advantage of protein precipitation by TCA and PTA is that very small amounts of protein (of the order of 10 micrograms) can be repeatably recovered without the use of precipitate-bulking agents such as sodium deoxycholate. This general procedure of protein purification and concentration is simple and rapid, but the use of PTA may not be fully compatible with the Bradford protein assay. A modified Lowry microassay is described which enables about 3 micrograms ml-1 to be quantitated at the photometric absorbance of 0.05. When used in conjunction with protein concentration by precipitating with TCA/PTA, approximately 0.4 microgram ml-1 protein present in 6 ml of solution can be assayed.

Matched MeSH terms: Plant Proteins/isolation & purification