scholarly journals Immunochemical characterization of the platelet-specific alloantigen Leka: a comparative study with the PlA1 alloantigen

Blood ◽  
1984 ◽  
Vol 64 (6) ◽  
pp. 1212-1219 ◽  
Author(s):  
N Kieffer ◽  
B Boizard ◽  
D Didry ◽  
JL Wautier ◽  
AT Nurden

Abstract We report the immunochemical characterization of a new platelet- specific alloantigen detected using an IgG antibody isolated from the serum of a patient with posttransfusion purpura (PTP). In indirect immunoprecipitation experiments, the antibody, termed anti-Leka, predominantly precipitated glycoprotein (GP) IIb from Triton X-100 lysates of normal human platelets. In an immunoblot procedure, which involved the transfer of platelet polypeptides separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to nitrocellulose membrane, anti-Leka bound exclusively to GP IIb. Under identical conditions, four anti-PlA1 antibodies each reacted with GP IIIa. No binding of anti-Leka IgG occurred to Leka (-) platelets or to their separated polypeptides although GP IIb was normally detected by Coomassie blue staining. After electrophoresis of reduced platelet proteins, the Leka determinant was localized to the IIb alpha chain. Thus, unlike the PlA1 antigen, the Leka determinant was not destroyed by disulfide reduction. Analysis of platelets from a patient with Glanzmann's thrombasthenia revealed little or no binding in the GP IIb position. Anti-Leka permitted the identification of 76,000 and 60,000 dalton fragments of GP IIb retained by the platelet following chymotrypsin treatment. Our results further highlight the immunogenicity of the GP IIb-IIIa complex. They also suggest that antibodies against GP IIb can cause the thrombocytopenia observed in PTP and that anti-PlA1 antibodies do not account exclusively for the pathophysiology of this immune disorder.

Blood ◽  
1984 ◽  
Vol 64 (6) ◽  
pp. 1212-1219
Author(s):  
N Kieffer ◽  
B Boizard ◽  
D Didry ◽  
JL Wautier ◽  
AT Nurden

We report the immunochemical characterization of a new platelet- specific alloantigen detected using an IgG antibody isolated from the serum of a patient with posttransfusion purpura (PTP). In indirect immunoprecipitation experiments, the antibody, termed anti-Leka, predominantly precipitated glycoprotein (GP) IIb from Triton X-100 lysates of normal human platelets. In an immunoblot procedure, which involved the transfer of platelet polypeptides separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to nitrocellulose membrane, anti-Leka bound exclusively to GP IIb. Under identical conditions, four anti-PlA1 antibodies each reacted with GP IIIa. No binding of anti-Leka IgG occurred to Leka (-) platelets or to their separated polypeptides although GP IIb was normally detected by Coomassie blue staining. After electrophoresis of reduced platelet proteins, the Leka determinant was localized to the IIb alpha chain. Thus, unlike the PlA1 antigen, the Leka determinant was not destroyed by disulfide reduction. Analysis of platelets from a patient with Glanzmann's thrombasthenia revealed little or no binding in the GP IIb position. Anti-Leka permitted the identification of 76,000 and 60,000 dalton fragments of GP IIb retained by the platelet following chymotrypsin treatment. Our results further highlight the immunogenicity of the GP IIb-IIIa complex. They also suggest that antibodies against GP IIb can cause the thrombocytopenia observed in PTP and that anti-PlA1 antibodies do not account exclusively for the pathophysiology of this immune disorder.


1992 ◽  
Vol 4 (2) ◽  
pp. 249 ◽  
Author(s):  
A Paliwal ◽  
B Malaviya ◽  
VP Kamboj

Oviducts were obtained from monkeys on Days 8, 14, 19 and 25 of the menstrual cycle and changes in the pattern of luminal fluid proteins were examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric analysis after periodic acid Schiff's reagent (PAS) and coomassie blue staining of the gels revealed 85 and 95 kDa proteins only up to Day 14 whereas a 130 kDa glycoprotein persisted up to Day 19 and reached a nadir at mid-menstrual cycle (Day 14). The absence of the 130 kDa glycoprotein in the serum and its presence in cytosolic preparations up to Day 19 suggest that it is of oviductal origin. The 130 kDa glycoprotein is of particular interest since it was present in the oviductal fluid during mid cycle, a period when the oviduct participates in gamete transport, fertilization and embryo development. The conclusion drawn from this study is that the protein profile of monkey oviductal fluid changes during the menstrual cycle.


1987 ◽  
Vol 33 (10) ◽  
pp. 1886-1887 ◽  
Author(s):  
T Marshall ◽  
K M Williams

Abstract We applied a simple sodium dodecyl sulfate-polyacrylamide gel electrophoresis method to urine. The method, developed for serum protein analysis (Clin Chem 1984;30:475-9), has a high sample throughput and gives excellent resolution with unconcentrated urine. It clearly distinguishes and characterizes proteinuric urine (7.5 microL) by Coomassie Blue staining and gives complex silver-stained patterns with nonproteinuric urine (2 microL). The former is recommended for routine clinical screening, the latter for research purposes.


1981 ◽  
Author(s):  
A T Nurden ◽  
D Dupuis

Both platelet membrane GP Ib and GP V have been proposed as receptors for the activation of human platelets by thrombin. Bernard-Soulier (B-S) platelets exhibit a reduced aggregation response to thrombin with a lag phase that precedes aggregation. When B-S platelets, whose surface proteins had been labelled with (125I), were analysed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) followed by PAS-staining, Coomassie blue staining or autoradiography, the apparent absence of GP Ib and the normal presence of GP IIb, IIIa and IIIb was demonstrated. On the basis of such studies several authors have stated that “GP I” is the thrombin receptor. However, GP V is not located by the above procedure, requiring more sensitive analytical methods for its detection. To meet this requirement washed platelets isolated from 3 B-S patients have been treated sequentially with neuraminidase, galactose oxidase and sodium(3H,)-boro- hydride. The labelled platelets were analysed by SDS-PAGE using 7-12% gradient acrylamide gels and the (3H,)-labelled GP’s located by fluorography. In addition to the GP Ib defect the platelets of each B-S patient were lacking the band corresponding to GP V of normal platelets. In agreement with previous studies we observed that when (3H,)-labelled normal human platelets were incubated with thrombin GP V (Mr=82,000) was hydrolysed,and that this was accompanied by the appearance of a labelled glycopeptide (Mr=69,500) in the supernatant. When (3H)-labelled B-S platelets were treated with thrombin no labelled glycopeptide was located. GP V could therefore be either absetit from B-S platelets or have a modified carbohydrate composition rendering it insensitive to the analytical procedure used. Interpretations into the reduced aggregation response of B-S platelets to thrombin should be extended to include a possible GP V defect.


1984 ◽  
Vol 217 (1) ◽  
pp. 129-133 ◽  
Author(s):  
L J Takemoto ◽  
J Hansen ◽  
D B Farber ◽  
D Souza ◽  
D J Takemoto

A light-activated phosphodiesterase (PDE) from retinal rod outer segments (ROS) has been strongly implicated as a possible mediator in the propagation of the visual response. In view of the probable importance of this enzyme in the visual system, a comparison of the PDE proteins from ROS of different evolutionary species was made. Partial purification of the PDE, as measured by enzymic activity, followed by resolution of the protein components on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, indicated that the major Coomassie Blue-staining species in the ROS of all species studied is a doublet of 84000-88000 Da. After radioiodination, this doublet was converted in all but the frog proteins into a single band of 85000 Da. Two-dimensional tryptic peptide mapping of the radioiodinated peptides indicated that at least six major peptides of the putative PDE have been conserved in all of the species studies. If this protein is indeed associated with PDE activity, such conserved peptides may play an important role in the catalytic and/or regulatory functions of the enzyme.


1989 ◽  
Vol 260 (3) ◽  
pp. 641-646 ◽  
Author(s):  
C N Falany ◽  
M E Vazquez ◽  
J M Kalb

A form of sulphotransferase capable of sulphating dehydroepiandrosterone and other steroids was purified from cytosol prepared from human liver. Dehydroepiandrosterone sulphotransferase was purified 621-fold when compared with the activity in cytosol using DEAE-Sepharose CL-6B and adenosine 3′,5′-bisphosphate-agarose affinity chromatography. During affinity chromatography, dehydroepiandrosterone sulphation activity could be resolved from p-nitrophenol sulphation activity catalysed by phenol sulphotransferase by using a gradient of adenosine 3′-phosphate 5′-phosphosulphate. The purified enzyme was most active towards dehydroepiandrosterone but was capable of conjugating a number of other steroids, including pregnenolone, androsterone and beta-oestradiol. No activity towards p-nitrophenol or dopamine, substrates for the phenol sulphotransferase, was observed with the pure enzyme. A single band with a subunit molecular mass of 35 kDa was observed by Coomassie Blue staining following SDS/polyacrylamide-gel electrophoresis of the purified enzyme. A molecular mass of 68-70 kDa was calculated for the active form of the enzyme by chromatography on Sephacryl S-200, suggesting that the active form of the enzyme is a dimer.


1983 ◽  
Vol 61 (7) ◽  
pp. 756-763 ◽  
Author(s):  
Jean Y. Dubé ◽  
Pierre Chapdelaine ◽  
Roland R. Tremblay

We have submitted adult mongrel dogs to various endocrine manipulations. Prostate slices from these animals were then incubated in vitro in the presence of [3H]leucine or [35S]methionine. We have analyzed the cytosolic proteins by polyacrylamide gel electrophoresis. In intact adult uncastrated dogs, the radioactive amino acids were incorporated into three major bands having respective molecular weights (MW) of 32 000,16 000, and 15 000 in one-dimensional gels in presence of sodium dodecyl sulfate and mercaptoethanol. Two-dimensional electrophoresis revealed heterogeneity of each of these bands, both in isoelectric focussing (IEF) or nonequilibrium pH gel electrophoresis (NEpHGE) conditions. The 32 000 MW proteins showed five to six major radioactive spots and the 15 000 – 16 000 MW proteins showed six to seven spots by IEF. However, the highest incorporation of radioactivity occurred in a 16 000 MW protein seen only in NEpHGE. The lower MW proteins corresponded to some of the major proteins of dog seminal plasma as observed by immunoprecipitation of prostate proteins with antibodies against whole seminal plasma. By contrast, the 32 000 MW proteins were minor proteins of prostate cytosol and seminal plasma by Coomassie blue staining. Castration for 2 weeks completely abolished the synthesis of all these proteins. When castrated animals were treated with 5α-androstane-3α-17β-diol (10 mg/day for 2 weeks), the pattern of protein synthesis returned to the one observed in intact uncastrated animals. These observations show that testicular androgens control the synthesis of dog prostate major secretory proteins.


1977 ◽  
Vol 55 (9) ◽  
pp. 988-994 ◽  
Author(s):  
A. McGeer ◽  
B. Lavers ◽  
G. R. Williams

Beef heart cytochrome oxidase (EC 1.9.3.1) prepared in this laboratory consistently presents 10 Coomassie blue staining zones on SDS–polyacrylamide gel electrophoresis. At pH 7.0 only two of these polypeptides (III and VIa) are labelled by radioactive N-ethyl maleimide (NEM). The labelling of VIa is variable and correlates with the activity of particular oxidase preparations. When cytochrome oxidase is isolated from alkylated membranes, either mitochondria or electron transport particles, polypeptide VIa is found not to be labelled; polypeptide III is more strongly labelled than when isolated oxidase is alkylated, and label now appears in polypeptide I which is not alkylated upon treatment of isolated oxidase with NEM.


1981 ◽  
Author(s):  
A K Rao ◽  
G P Tuszynski ◽  
L Knight ◽  
J Willis ◽  
C Beckett

Platelets stored as concentrates (PC) at 22° C for 72 hours develop a functional defect in vitro tests. Alterations in membrane glycoproteins of platelets have been shown to effect platelet function. We have investigated the effect of storage on membrane glycoproteins (GP) and cytoskeletons (cyto.) of platelets. Gel filtered platelets from fresh PC were labeled with 125Iodine by Iodogen technique and gel filtered again to remove free iodide. Platelets were concentrated by albumin density gradient centrifugation, resuspended in autologous plasma and stored for 72 hours at 22° C. Aliquots of fresh and stored PC were solubilized with 2% sodium dodecyl sulphate (SDS) containing 5% mercaptoethanol and subjected to polyacrylamide gel electrophoresis (PAGE). In one experiment, separate aliquots of fresh and stored platelets were labeled and similarly analyzed. Gels were stained with Coomassie blue and subjected to autoradiography. Coomassie blue staining did not reveal major differences between fresh and stored platelets. Autoradiography revealed a decrease in the 170,000 dalton surface protein (GP-I) of platelets after storage. Triton insoluble cyto. of thrombin activated fresh and stored platelets were solubilized with SDS and analyzed by PAGE and autoradiography. Cytoskeletons from fresh PC revealed the presence of a 110,000 dalton surface protein (GP-III). However, cyto. from similarly treated stored platelets showed a markedly decreased amount of this protein. Thus stored platelets have decreased amounts of the 170,000 dalton surface protein (GP-I) along with decreased amounts of the 110,000 dalton protein (GP-III) associated with the cyto. of thrombin activated platelets. These changes may contribute to the functional defect reported in stored platelets.


1983 ◽  
Vol 31 (6) ◽  
pp. 709-716 ◽  
Author(s):  
M R Green

Proteins in colostrum and skimmed milk from humans and mice were separated by electrophoresis on polyacrylamide gels and stained with Coomassie blue (CB), Ethyl-Stains-all (ESA), and periodic acid-Schiff (PAS) to investigate changes that may occur in milks throughout lactation. In mouse colostrum but not in mature mouse milk, a PAS-positive protein of apparent molecular weight of 60,000 stained prominently blue with ESA. A protein in human milk with a molecular weight of 68,000 stained similarly but was present throughout lactation. The intensity of blue staining of these minor proteins in milk approached that obtained with casein phosphoproteins. The metachromatic dye ESA stains phosphoproteins and sialic acid-rich glycoproteins blue to blue-green. Removal of phosphorus from the former and sialic acid from the latter results in those proteins staining red with ESA. The intensity of blue staining of the 60,000 and 68,000 Mr proteins was diminished but not lost following treatment with phosphatase. It was eliminated following neuraminidase digestion of the mouse protein and mild acid hydrolysis of the human protein. Coomassie blue staining of the proteins was not affected by these procedures. Following electrophoresis of milk and milk fractions in a non-sodium dodecyl sulfate-containing system, the proteins were identified by their characteristic staining properties with ESA and isolated.


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