scholarly journals Homodimer and heterodimer subunits of human prostate acid phosphatase

1991 ◽  
Vol 277 (3) ◽  
pp. 759-765 ◽  
Author(s):  
H Lee ◽  
T M Chu ◽  
S S L Li ◽  
C L Lee

Human prostatic acid phosphatase (PAP) isoenzymes, designated PAP-A and PAP-B, were isolated from human seminal plasma by sequential affinity chromatography on concanavalin A and L(+)-tartrate, a classic inhibitor of PAP. Both the major PAP-A and the minor PAP-B isoenzymes exhibited a similar molecular mass (100 and 105 kDa respectively), multiple pI values (5.05-5.35 and 5.05-5.12), and substrate and inhibitor specificity. Immunological characterization revealed that PAP-B possesses distinct antigenic determinants, in addition to the common sites shared with PAP-A. SDS/PAGE indicated that both isoenzymes are composed of two subunits of 50 kDa each. At high salt concentration, PAP-B dissociated completely into single subunits of 50 kDa, whereas PAP-A remained intact at 100 kDa. PAP-B was resolved by reverse-phase h.p.l.c. into three components, designated alpha, beta and gamma, each of 50 kDa, at a molar ratio of approx. 2:1:1. PAP-A contained a single component of molecular mass 50 kDa. The single component of PAP-A and the alpha component of PAP-B possessed identical amino acid compositions and N-terminal sequences, which were different from those of the beta and gamma components. These results indicate that human PAP contains three isoforms, alpha 2, alpha beta and alpha gamma. PAP-A, the major isoenzyme, is a homodimer consisting of two identical subunits (alpha 2), and PAP-B, the minor isoenzyme, is a mixture of two heterodimers, consisting of non-identical subunits (alpha beta and alpha gamma).

1987 ◽  
Vol 65 (10) ◽  
pp. 921-924 ◽  
Author(s):  
Gilles Paradis ◽  
Jean Y. Dubé ◽  
Pierre Chapdelaine ◽  
Roland R. Tremblay

Poly(A)+ RNA was isolated from human prostatic tissue and translated in vitro in a rabbit reticulocyte lysate translation assay. Acid phosphatase labeled with [35S]methionine was immunoprecipitated with an antibody against seminal plasma acid phosphatase. Two-dimensional polyacrylamide gel electrophoresis of the immunoprecipitate, followed by fluorography, revealed the presence of two spots (one major and one minor), both having a molecular mass of 43 kilodaltons (kDa) and an isoelectric point higher than mature acid phosphatase. Addition of canine pancreatic membranes to the translation assay resulted in the formation of four immunoprecipitable spots with molecular masses ranging from 43 to 49 kDa on one-dimensional gels. These spots probably represent acid phosphatases containing one to four core sugar groups, since after the addition of endoglycosidase H the molecular mass heterogeneity was abolished and we observed only one major band with a molecular mass (41 kDa) slightly lower than the ones of the primary translation product. These results suggest that human prostatic acid phosphatases are synthesized as two 43-kDa preproteins, which are further processed to 41-kDa proteins by removal of their signal peptide. Heterogeneity of the native protein arises mostly from glycosylation at four sites and not from differences in the amino acid sequence of the various forms.


PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e58631 ◽  
Author(s):  
Jenifer H. Anklesaria ◽  
Dhanashree D. Jagtap ◽  
Bhakti R. Pathak ◽  
Kaushiki M. Kadam ◽  
Shaini Joseph ◽  
...  

1994 ◽  
Vol 107 (4) ◽  
pp. 945-953 ◽  
Author(s):  
S.E. Holstein ◽  
M. Drucker ◽  
D.G. Robinson

Plant clathrin-coated vesicles (CCV), suitably protected against proteolysis, were isolated from zucchini hypocotyls, and screened for the presence of adaptin-like polypeptides using monoclonal antibodies prepared against alpha, beta(beta') and gamma-adaptins of bovine brain. An immunoreactive polypeptide in plant CCV was only detected in the case of the beta(beta')-adaptin antibody. This polypeptide has a molecular mass of 108 kDa in SDS-PAGE, and gives rise to a major cleavage product of 70 kDa after proteolysis with trypsin. Gel filtration of 0.75 M MgCl2-dissociated coat proteins showed that the plant beta(beta')-type adaptin eluted with other polypeptides in a manner similar to the adaptor complexes of brain CCV. Upon subsequent hydroxyapatite chromatography the immunoreactive polypeptide eluted in fractions corresponding to Golgi (HA-I) rather than plasma membrane (HA-II) brain adaptor complexes. In addition, this polypeptide did not shift to a higher molecular mass when subjected to urea-SDS-PAGE. Confirmation of the presence of a beta-type adaptin in plants was provided by dot and Southern blotting experiments using genomic DNA from zucchini hypocotyls and a beta-adaptin cDNA clone from human fibroblasts.


1992 ◽  
Vol 66 (1) ◽  
pp. 38-44 ◽  
Author(s):  
R. C. Ko ◽  
T. P. Wong

ABSTRACTExcretory/secretory (ES) antigens were obtained by culturing pre-encysted Trichinella spiralis larvae which were recovered from muscles of experimentally infected mice 14–15 days postinfection. Analyses of these antigens (PEL ES) with immunoblotting, SDS-PAGE and Triple Antibody ELISA showed that they yielded a low sensitivity and specificity when tested antisera against the common nematodes of Chinese pigs. As compared to ES antigens from encysted larvae. PEL ES also contained more low molecular mass proteins.


PLoS ONE ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. e16285 ◽  
Author(s):  
Julie A. Martellini ◽  
Amy L. Cole ◽  
Pavel Svoboda ◽  
Olga Stuchlik ◽  
Li-Mei Chen ◽  
...  

1990 ◽  
Vol 36 (8) ◽  
pp. 1450-1455 ◽  
Author(s):  
Linh Nguyen ◽  
Alcide Chapdelaine ◽  
Simone Chevalier

Abstract We developed an assay to measure at acid pH the phosphotyrosine phosphatase activity in sera from patients with prostatic cancer. The method used quantifies the inorganic phosphate liberated from phosphotyrosine after incubation with serum, followed by the deproteinization of the reaction mixture. A high acid phosphatase (EC 3.1.3.2) activity towards phosphotyrosine was observed in all sera from patients with increased activity of prostatic acid phosphatase. This activity represented 96% of prostatic acid phosphatase and 77% of total acid phosphatase activities. Moreover, it was correlated (r = 0.91) with the amount of serum prostatic acid phosphatase determined by radioimmunoassay. When serum acid phosphatase activity was measured on several phosphorylated substrates, preferential hydrolysis was demonstrated for those in which the phosphate group was esterified on an aromatic ring rather than those presenting an aliphatic chain. Among phosphoamino acids, only phosphotyrosine was a good substrate, with little or no activity observed with phosphoserine and phosphothreonine. Human seminal plasma and partially purified prostatic acid phosphatase, tested for their activity on some of these substrates, gave similar results. On the other hand, sera from patients with above-normal alkaline phosphatase activity and no prostatic disease showed little or no activity on phosphotyrosine at both acid and alkaline pH values. Evidence is presented that the prostatic acid phosphatase in serum is a specific phosphotyrosine acid phosphatase.


Author(s):  
José A. Serrano ◽  
Hannah L. Wasserkrug ◽  
Anna A. Serrano ◽  
Arnold M. Seligman

As previously reported (1, 2) phosphorylcholine (PC) is a specific substrate for prostatatic acid phosphatase (PAP) as opposed to other acid phosphatases, e.g., lysosomal acid phosphatase. The specificity of PC for PAP is due to the pentavalent nitrogen in PC, a feature that renders PC resistant to hydrolysis by all other acid phosphatases. Detailed comparative cytochemical results in rat tissues are in press. This report deals with ultracytochemical results applying the method to normal and pathological human prostate gland.Fresh human prostate was obtained from 7 patients having transurethral resections or radical prostatectomies. The tissue was fixed in 3% glutaraldehyde- 0.1 M cacodylate buffer (pH 7.4) for 15 min, sectioned at 50 μm on a Sorvall TC-2 tissue sectioner, refixed for a total of 2 hr, and rinsed overnight in 0.1 M cacodylate buffer (pH 7.4)-7.5% sucrose.


Author(s):  
W. Allen Shannon ◽  
José A. Serrano ◽  
Hannah L. Wasserkrug ◽  
Anna A. Serrano ◽  
Arnold M. Seligman

During the design and synthesis of new chemotherapeutic agents for prostatic carcinoma based on phosphorylated agents which might be enzyme-activated to cytotoxicity, phosphorylcholine, [(CH3)3+NCH2CH2OPO3Ca]Cl-, has been indicated to be a very specific substrate for prostatic acid phosphatase (PAP). This phenomenon has led to the development of specific histochemical and ultracytochemical methods for PAP using modifications of the Gomori lead method for acid phosphatase. Comparative histochemical results in prostate and kidney of the rat have been published earlier with phosphorylcholine (PC) and β-glycerophosphate (βGP). We now report the ultracytochemical results.Minced tissues were fixed in 3% glutaraldehyde-0.1 M phosphate buffered (pH 7.4) for 1.5 hr and rinsed overnight in several changes of 0.05 M phosphate buffer (pH 7.0) containing 7.5% sucrose. Tissues were incubated 30 min to 2 hr in Gomori acid phosphatase medium (2) containing 0.1 M substrate, either PC or βGP.


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