Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “peanut”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50Linked to original sources
PubMed2006

Thermodynamic analysis of three state denaturation of Peanut Agglutinin.

Peanut Agglutinin (PNA) is a homotetrameric protein with a very unusual open quaternary structure. During denaturation, it first dissociates into a molten globule like state, which subsequently undergoes complete denaturation. Urea denaturation of PNA at neutral pH has been studied by intrinsic fluorescence spectroscopy and has been fitted to a three state model, A4 <=> 4I <=> 4U, to get all the relevant thermodynamic parameters. Urea denaturation leads to continuous red shift of wavelength maxima. The molten globule like state is formed in a short range of urea concentration. Refolding of the denatured PNA has been attempted by intrinsic fluorescence study. Refolding by instantaneous dilution shows the occurrence of the formation of an intermediate at a relatively rapid rate, within few seconds. The transition from PNA tetramer to molten globule like state is found to have a DeltaG value of approximately 33 kcal/mole while it is approximately 8 kcal/mole for the transition from molten globule like state to a completely denatured state. This in turn indicates that the tetramerization in PNA contributes significantly to the stability of the oligomer.

Dose-Response Relationship, Drug↗
PubMed1987

Biological observations from feeding heated corn oil and heated peanut oil to rats.

Five groups of male weanling rats were provided purified diets containing 15% by weight of either fresh or laboratory-heated corn oil (FCO, HCO) or fresh, laboratory-heated, or commercial pressure deep-fry peanut oil (FPO, HPO, PPO). Total weight gain, feed consumption, and feed efficiency were consistently greater for the FCO, FPO, and PPO groups. Although relative heart weights were unaffected, the HCO and HPO produced elevated liver and kidney weights. The dietary fats had no effect on the hematological status of the animals or the proportions of cells comprising the total leukocytes of the blood. Physical, chemical, and microscopic evaluation of the urine detected no pathologic conditions. Rats fed diets containing HCO or HPO demonstrated toxicity of thermally oxidized fats by the appearance of diarrhea, dermatitis, seborrhea, and hair loss. Histological examinations revealed injury of the thymus by all fat samples except the FCO; the liver was damaged by the HCO, HPO, and PPO, and the testes and epididymides by HPO and PPO. In the latter case there was complete cessation of spermatogenesis.

Animals↗
PubMed2003

Antioxidant activities of rosemary, sage, and sumac extracts and their combinations on stability of natural peanut oil.

The antioxidant efficacy of rosemary (Rosmarinus officinalis L.), sage (Salvia fruticosa L.), and sumac (Rhus coriaria L.) extracts and combinations at 4% concentrations (wt/vol, extract/oil) were investigated. Methanolic extracts of rosemary, sage, sumac, and their combinations were applied to peanut oil stored at 80 degrees C for 24 h. The antioxidant effect was determined by measuring the peroxide value. All extracts showed antioxidant effects compared with control. But the antioxidant effect of all extracts was low compared with that of butylated hydroxytoluene. Rosemary extract (except for 3 and 4 h) exhibited the most antioxidant effect compared with other individual extracts. Of blends, the most effective ones were sage plus sumac combinations. Sumac extract is also promising as a source of natural antioxidants.

Antioxidants↗
PubMed1982

Peanut agglutinin: a new marker for tissue histiocytes.

The histiocyte (macrophage) is a unique cellular constituent of the immune system which is involved in immune and non-immune cellular reactions, as well as in the genesis of a variety of benign and malignant neoplasms. The ability to distinguish histiocytes from similar appearing cells morphologically, is often difficult, yet may be of considerable practical and theoretical importance. The present study describes a new marker for histiocytes, applicable to routinely processed tissues. An immunoperoxidase procedure to detect binding of peanut agglutinin (PNA) was applied to 58 specimens consisting of lymph nodes, extranodal lymphoid tissues, neoplasms and reactive histiocytic lesions. Results were compared with a currently accepted histiocytic marker--cytoplasmic muramidase. Of the 58 tissues, 51 showed PNA binding to morphologically recognizable histiocytes, whereas muramidase was detected in only 44. PNA binding- appeared at least as sensitive and specific as muramidase, as a marker for histiocytes, and offers the advantage that it does not bind to cells of the granulocytic series.

Cytoplasm↗
PubMed1990

Histiocytosis X. S-100 protein, peanut agglutinin, and transmission electron microscopy study.

Twenty-seven cases of histiocytosis X (HX) for which paraffin blocks were available were studied with the use of S-100 protein immunohistochemistry, peanut agglutinin affinity histochemistry, and transmission electron microscopy. The results show that these techniques did enable identification of Langerhans'-type histiocytes in 88.5%, 75%, and 47.4% of cases, respectively. All techniques were proved to be of some diagnostic value for HX, but none was able to confirm the diagnosis in all instances and none could foretell the prognosis of the patients. This study shows that besides the Langerhans' cells, the indeterminate cells of the skin and the interdigitating dendritic reticulum cells of the lymph node may also be involved in this process. Moreover, some multinucleate giant cells and foamy cells may be derived from Langerhans' and related cells.

Adolescent↗
PubMed2026

Long-read low-pass sequencing enhances variant detection in a peanut MAGIC population.

Accurate genotyping accelerates crop improvement, yet long-read sequencing remains underused in breeding due to cost. We present a scalable long-read low-pass (LRLP) sequencing framework for high-throughput variant discovery and trait mapping. Using PacBio HiFi reads in an allotetraploid peanut (Arachis hypogaea; AABB, 2n = 4x = 40) MAGIC population, we generated both LRLP and short-read low-pass (SRLP) data. At comparable depths, LRLP achieved substantially greater whole-genome and gene-space coverage than SRLP. Data were analyzed using both a single-reference genome and an 18-parent pangenome graph constructed with KhufuPan, a new tool for graph-based genotyping. Across analytical approaches, LRLP consistently identified more SNPs, indels (2-1,000 bp), and structural variants (>1 kb) than SRLP, improving genotype resolution and selection accuracy, particularly for large structural variants. By reducing cost barriers and increasing variant discovery in complex genomes, LRLP provides a practical path for deploying advanced genomics in under-resourced and orphan crops critical to global food security.

Arachis↗
PubMed1997

Developmentally regulated expression of peanut agglutinin (PNA)-specific glycans on murine thymocytes.

Intrathymic maturation of T lymphocytes is characterized by variable expression of O-linked Gal beta 1,3GalNAc glycans reactive with peanut agglutinin (PNA) lectin. Recent studies on human thymocytes show that conversion from PNA+ to PNA- phenotype is correlated with increased expression of alpha 2,3 O-linked sialyltransferase (ST), which sialylates Gal beta 1,3GalNAc glycans, masking their binding sites for PNA. Interestingly, alpha 2,3 O-linked ST expression is highest within the regions of the thymus containing the most immature and most mature thymocyte subsets, suggesting that PNA-specific glycans are intermittently masked by sialylation during thymic selection processes. Here, we studied expression of PNA receptors on developing thymocytes in the murine system using thymocytes from both normal mice and transgenic mice that are genetically arrested at the early phases of T cell development. Our results confirm and extend recent findings in the human system by showing that murine T cells sequentially progress from PNAlo-->PNAhi-->PNAlo stages during their differentiation within the thymus. In addition, our data demonstrate that a similar set of polypeptides is variably masked by sialylation throughout T cell development.

Animals↗
PubMed1998

Molecular basis of recognition by Gal/GalNAc specific legume lectins: influence of Glu 129 on the specificity of peanut agglutinin (PNA) towards C2-substituents of galactose.

The ability to discriminate between galactose and N- acetylgalactosamine, observed in some lectins, is crucial for their biological activity as well as their usefulness as tools in biology and medicine. However, the molecular basis of differential binding of lectins to these two sugars is poorly understood. Peanut agglutinin (PNA) is one of the few galactose-specific legume lectins which does not bind N- acetylgalactosamine at all and is, therefore, ideal for the study of the basis of specificity towards C-2 substituted derivatives of galactopyranosides. Examination of the three-dimensional structure of PNA in complex with lactose revealed the presence of both a longer loop and bulkier residues in the region surrounding the C-2 hydroxyl of the galactopyranoside ring, which can sterically prevent the accommodation of a bulky substituent in this position. One such residue, is a glutamic acid at position 129 which protrudes into the binding site and perhaps directly obstructs any substitution at the C-2 position. Two mutants in bacterially expressed PNA were therefore constructed. These were E129D and E129A, in which Glu129 was replaced by Asp and Ala, respectively. The specificity of the mutants for galactose, galactosamine, and N- acetylgalactosamine was examined through observing the inhibition of hemagglutination and binding of the lectin to immobilized asialofetuin. The results showed that the affinity of E129A and E129D for C-2-substituted derivatives of the galactose varies. The mutant E129D showed significant binding towards N- acetylgalactosamine, suggesting that the residue Glu 129 is crucial in imparting exclusive galactose-specificity upon PNA. This study not only attempts to provide an explanation for the inability of PNA to accommodate C-2-substituted derivatives at its primary subsite, but also seeks to present a basis for engineering lectins with altered specificities.

Acetylgalactosamine↗
PubMed2006

Peanut lectin stimulates proliferation of colon cancer cells by interaction with glycosylated CD44v6 isoforms and consequential activation of c-Met and MAPK: functional implications for disease-associated glycosylation changes.

Peanut agglutinin lectin (PNA) binds the Thomsen-Friedenreich (TF) oncofetal carbohydrate antigen (galactose beta1-3N-acetylgalactosamine alpha) that shows increased expression in colon cancer, adenomas, and inflammatory bowel disease. PNA is mitogenic, both in vitro and in vivo, for colon epithelial cells. In these cells, PNA binds predominantly to cell-surface TF antigen expressed by high molecular weight isoforms of the transmembrane glycoprotein CD44 that are generated in inflamed and neoplastic colonic epithelia by altered RNA splicing. Our aim was to identify the signaling mechanism underlying the proliferative response to PNA. This was investigated in HT29, T84, and Caco2 colon cancer cells. Parallel lectin and immunoblotting of PNA affinity-purified HT29 cell membrane extracts showed PNA binding to high molecular weight CD44v6 isoforms. Within 5 min, PNA (25 microg/mL) caused a 6-fold increase in phosphorylation of hepatocyte growth factor receptor c-Met, known to co-associate with CD44v6. This was followed by the downstream activation of p44/p42 mitogen-activated protein kinase (MAPK) over 15-20 min. The presence of 100 microg/mL asialofetuin, a TF antigen-expressing glycoprotein, blocked both PNA-induced c-Met and MAPK activation. A similar PNA-induced c-Met and MAPK phosphorylation was also seen in T84 cells that express CD44v6 but not in Caco2 cells that lack CD44v6. PNA-induced cell proliferation was completely blocked by 1 microM PD98059, an inhibitor of MAPK activation (p < 0.0001). The expression of TF antigen by CD44 isoforms in colonic epithelial cells allows lectin-induced mitogenesis that is mediated by phosphorylation of c-Met and MAPK. It provides a mechanism by which dietary, microbial, or endogenous galactose-binding lectins could affect epithelial proliferation in the cancerous and precancerous colon.

Cell Line, Tumor↗
PubMed1990

Combined use of fluorescent peanut agglutinin lectin and Hoechst 33258 to monitor the acrosomal status and vitality of human spermatozoa.

Fluorescein-conjugated peanut agglutinin (PNA) lectin-labelling is an established procedure for assessing the status of the human sperm acrosome. However, unlike the triple-stain technique, PNA-labelling does not provide a simultaneous assessment of cellular vitality. We have therefore evaluated the use of the fluorescent dye Hoechst 33258 (H33258) as a vital stain for use in combination with PNA-labelling. Human sperm populations were stained for 1 min with 1 microgram/ml H33258 in culture medium and then washed through 2.0 (w/v) polyvinylpyrollidone columns and air-dried onto microscope slides. H33258 was found to provide vitality assessments comparable to those obtained using the standard eosin-exclusion method. However, best results were obtained with an ethanol fixation step between air-drying and PNA-labelling. This vitality assessment was found to be more reliable than that provided by Trypan blue staining under conditions equivalent to the triple-stain technique. There was no alteration of PNA-labelling due to the H33258 although ethanol fixation actually provided more uniform PNA-labelling than previously obtained without ethanol fixation. Consequently, we have stopped using the triple-stain technique for assessing human sperm acrosome reactions and now use the H33258/PNA procedure routinely.

Acrosome↗
PubMed1993

Comparison between fluorescent peanut agglutinin lectin and GB24 antibody techniques for the assessment of acrosomal status.

In order to compare fluorescent peanut (Arachis hypogaea) agglutinin lectin and GB24 antibody (specific for the inner acrosomal membrane) techniques for the assessment of acrosome reaction, both methods were applied on semen specimens obtained from patients undergoing in-vitro fertilization (IVF). The acrosome status was evaluated after a 4 h incubation in B2 medium with and without calcium ionophore A23187. Results obtained with both techniques were compared and studied as a function of IVF outcome. The percentage of spontaneous acrosome-reacted spermatozoa was higher when assessed by lectin than by GB24 (19 +/- 2% versus 11 +/- 1%; P < 0.001). The difference between the two methods (lectins minus GB24) was significantly higher in abnormal than in normal spermatozoa (10 +/- 2% versus 4 +/- 2%; P < 0.05), but did not significantly correlate with the percentage of acrosomes with abnormal morphology (r = 0.28; NS). When studied in relation to the IVF results, the response to A23187 was higher in successes than in failures (45 +/- 2% versus 34 +/- 4%; P < 0.05) but there was no significant difference between methods. Thus the assessment of acrosome reaction is strongly influenced by the method used, particularly in abnormal spermatozoa. Since the results obtained with lectins were higher in abnormal spermatozoa, GB24 seems to be more effective for assessment of true acrosome reaction.

Acrosome↗
PubMed1982

Involvement of a tyrosyl residue in the interaction of peanut lectin with lactose.

The role of a tyrosyl residue in the binding of Arachis hypogaea (peanut) agglutinin, AHA, to lactose has been studied using two techniques, titration of the phenolic hydroxyl group of the tyrosine residue and chemical modification of the tyrosine with iodine. More than three tyrosyl residues per mol of AHA were masked when AHA was titrated in the presence of lactose. Lactose also protected some tyrosyl residues of AHA from the modification with iodine. Upon interaction with lactose, AHA iodinated in the presence of lactose gave a UV-difference spectrum with similar peaks to those of native AHA, while AHA iodinated in the absence of lactose gave a spectrum without such peaks. Though not only native AHA but also iodinated AHA was completely adsorbed on a column of lactamyl-Sepharose 6B, equilibrium dialysis showed that the binding constant and the number of binding sites of native AHA and iodinated AHA with lactose were 4.3 x 10(3) and 3.0 x 10(3) M-1, and 3.2 and 1.8, respectively. These results suggest that about two of four sugar binding sites have tyrosyl residues which induce the UV-difference spectra upon binding with lactose, and that the iodination of these tyrosyl residues results in a decrease of the number of binding sites on AHA.

Arachis↗
PubMed1985

Separation of germ cells from somatic cells in mouse testis by affinity for a lectin, peanut agglutinin.

A new method for the separation of germ cells from somatic cells in the mouse testis was accomplished by making use of the differences in cell surface affinity for a lectin, peanut agglutinin (PNA). The separation procedure was based on the specific presence of PNA receptor on testicular germ cells and its absence on somatic cells, such as Leydig, Sertoli and peritubular cells. As a result, more than 99% of cells in PNA receptor-positive (PNA+) fractions were identified as germ cells by immunoperoxidase reaction with specific antiserum to mouse testicular germ cells. In contrast, Leydig cells were enriched in PNA receptor-negative (PNA-) fractions, i.e., 65% of cells in these fractions were cytochemically stained for 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity.

Animals↗
PubMed1998

The use of immunostaining for bcl-2 and CD34 and the lectin peanut agglutinin in differentiating between basal cell carcinomas and trichoepitheliomas.

Fifteen unequivocal basal cell carcinomas (BCC) and ten unequivocal trichoepitheliomas (TE) were studied using the lectin peanut agglutinin (PNA), and the monoclonal antibodies Q bend 10 and bcl-2 oncoprotein directed against the antigens CD34 and bcl-2, respectively, to see whether these markers could be used to differentiate between the two tumors. Ten percent of TE demonstrated a continuous band-like peritumorous staining with PNA and 80% demonstrated a discontinuous band-like peritumorous staining with PNA, with the comparable figures for BCC being 40% and 20%, respectively. In addition, 40% of BCC showed focal areas of pemphigus-like staining in contrast with only 10% of TE. Using the antibody directed against bcl-2, TE demonstrated weak staining mainly confined to the basal layer of tumor cells in 20% of cases and staining of the cells throughout the tumor in 30% of cases. Similarly, BCC also showed staining of the basal layer of tumor cells in 7% of specimens and staining of cells throughout the tumor mass in 40% of specimens studied. Finally, with the antibody Q bend 10 directed against CD34, staining of the immediate peritumoral spindle-shaped cells was observed in 20% of TE compared with 7% of BCC. Despite reports in the literature, we found that none of these three markers can be reliably used to differentiate between TE and BCC.

Antigens, CD34↗
PubMed2003

Urea restrains aldosterone-induced development of peanut agglutinin-binding on embryonic renal collecting duct epithelia.

Peanut agglutinin (PNA) represents a commonly used marker for beta-type intercalated (IC) cells and their distribution in the corticomedullary course of the collecting duct (CD) in the mature rabbit kidney. It has been shown that aldosterone is able to generate >90% of PNA-binding cells in an embryonic CD epithelium in vitro. In adult kidney, a maximum of only 25% PNA-positive cells is found in the cortical segment of the CD, and PNA-binding completely disappears in the inner-medullary CD. Molecules that regulate the gradual development of CD-specific cells during organ growth are unknown. In the present experiments, it was found that addition of physiologic concentrations of urea to the culture medium is able to restrain the action of aldosterone in embryonic CD epithelia. Urea antagonizes in a concentration-dependent manner the action of aldosterone finally leading to only 10% of PNA-binding cells. The data point to a urea-specific effect, because osmolytes such as NaCl and mannitol did not affect PNA binding. In addition, urea did not influence expression of principal-cell typical markers such as AQP2 and 3. The findings may explain that a higher number of PNA-positive cells is found in the cortical region of the kidney correlated with a low concentration of urea as compared with only few PNA-binding cells in the medullary CD, where a high concentration of urea occurs. Thus, an increasing concentration of urea may trigger the number of PNA-positive cells in the cortical-medullary course of the CD during organ development.

Aldosterone↗
PubMed2006

Structural studies on peanut lectin complexed with disaccharides involving different linkages: further insights into the structure and interactions of the lectin.

Crystal structures of peanut lectin complexed with Galbeta1-3Gal, methyl-T-antigen, Galbeta1-6GalNAc, Galalpha1-3Gal and Galalpha1-6Glc and that of a crystal grown in the presence of Galalpha1-3Galbeta1-4Gal have been determined using data collected at 100 K. The use of water bridges as a strategy for generating carbohydrate specificity was previously deduced from the complexes of the lectin with lactose (Galbeta1-4Glc) and T-antigen (Galbeta1-3GalNAc). This has been confirmed by the analysis of the complexes with Galbeta1-3Gal and methyl-T-antigen (Galbeta1-3GalNAc-alpha-OMe). A detailed analysis of lectin-sugar interactions in the complexes shows that they are more extensive when the beta-anomer is involved in the linkage. As expected, the second sugar residue is ill-defined when the linkage is 1-->6. There are more than two dozen water molecules which occur in the hydration shells of all structures determined at resolutions better than 2.5 A. Most of them are involved in stabilizing the structure, particularly loops. Water molecules involved in lectin-sugar interactions are also substantially conserved. The lectin molecule is fairly rigid and does not appear to be affected by changes in temperature.

Disaccharides↗
PubMed1988

H-ras p21 and peanut lectin immunoreactivity of hyperplastic, preneoplastic and neoplastic urinary bladder lesions in rats.

Hyperplastic, preneoplastic and neoplastic urinary bladder lesions induced by bladder carcinogens and toxins in the rat were evaluated for immunoreactivity with polyclonal or monoclonal antibodies to H-ras p21 or binding to peanut lectin with avidin-biotin immunocytochemistry. A low proportion (less than 20%) of hyperplastic and neoplastic bladder lesions induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine and fixed in Bouin's fixative only were immunoreactive on the cell membrane with the antibodies to H-ras p21. Lectin binding was found for these lesions, as well, even in formalin-fixed tissue and for lesions induced by other carcinogens, but not in regenerative bladder hyperplasias after cyclophosphamide exposure or in bladder exposed to bladder tumor promoters. The latter lesions were also not immunoreactive with antibodies to p21. Our results suggest that this relatively simple technique might be used for identification and screening of tumors for involvement of ras oncogenes and carcinogen initiation.

Animals↗
PubMed1993

The peanut-agglutinin (PNA)-binding surface components of malignant plasma cells.

Plasma cells within bone marrow aspirates from multiple myeloma patients have been shown to be reactive with the lectin peanut agglutinin (PNA). This has been recently exploited by using PNA for purging bone marrow of malignant cells in autotransplantation therapy of the disease. The purpose of this investigation was to isolate and characterize the PNA-binding proteins of myeloma cells. We used the malignant plasma cell-derived line Karpas-620 (K620) as a model, and showed by affinity chromatography, SDS-PAGE, and immunoprecipitation that, among several PNA-binding proteins, a major one is an incompletely sialylated form of CD44. CD44 is a well-known homing receptor protein which is rich in carbohydrate and usually completely sialylated so that it does not react with PNA. We have then examined the PNA reactivity of myeloma cells from different patients and showed a clear difference in the profile of PNA-binding proteins from case to case. Moreover, in contrast to K620 cells, some of the patient plasma cells tested did not have a PNA-binding form of CD44. In conclusion, therefore, we have shown that a number of different proteins participate in PNA binding by malignant plasma cells. Moreover, we have demonstrated a novel, incompletely sialylated form of CD44 on a myeloma cell line. It is known that the level of glycosylation of CD44 and other proteins may affect their function, but how this relates to the malignant behaviour of plasma cells remains to be determined.

Bone Marrow↗