A quantitative study of the fixation of acid phosphatase by formaldehyde and its relevance to histochemistry

1974 ◽  
Vol 186 (1083) ◽  
pp. 137-164 ◽  

Fixatives reduce the activities of most enzymes in sections and blocks of tissue, but pre­vious studies do not agree by how much. In this paper it is shown that the disagreement is due principally to the use of inappropriate measurement parameters and to variations in the way tissues are prepared. Some new approaches to this problem are reported. They are illustrated by measurements on the activities of acid phosphatase (against p -nitrophenyl phosphate) remaining in blocks and cryostat-cut sections of hamster kidney after fixation in buffered solutions of formaldehyde. Whole fresh kidneys were cut into 1 mm 3 cubes. Two or more ‘lots’ of 9-12 cubes were chosen at random, fixed, washed, homogenized and assayed for residual enzyme specific activity which was expressed in terms of tissue nitrogen content or frozen-dried mass rather than protein content. The activity apparently remaining after fixation depends on, it was found, the time and temperature of fixation, the buffer salt in the fixative, the length of the post-fixation wash, and the duration and temperature of homogenization. For example, the relative activity (that is, specific activity expressed as a percentage of that of unfixed tissue) of acid phos­phatase in cubes assayed immediately after fixation is 46%; after a 24 h post-fixation wash in cold buffer it rises to 84%. Fixation causes only a 2% loss of nitrogenous material from the cubes. A further 2.7% is lost during the 24 h wash. Thus, much of the apparent loss of enzyme specific activity in fixed tissue is due to the inhibitory effects of fixative remaining in the tissue. Similar inhibition effects were observed in cryostat-cut sections, although sections frozen-dried on to coverslips showed a greater tolerance than fresh ones. For example, after 5 min fixation and without a post-fixation wash, the activity of acid phosphatase in fresh, cryostat-cut, mounted sections falls by about 30%, but that in frozen-dried ones is un­affected. After 25 min fixation, however the activity in the frozen-dried sections drops to about 84% of that of the unfixed tissue. A nitrogen-free buffer system, 5-norbornene-2, 3-dicarboxylic acid-NaOH, was used as the fixative vehicle for much of this study. A higher acid phosphatase activity is retained in tissues fixed or stored in this buffer than in either cacodylate or phosphate.

1986 ◽  
Vol 239 (1) ◽  
pp. 155-162 ◽  
Author(s):  
M Okada ◽  
K Owada ◽  
H Nakagawa

A [phosphotyrosine]protein phosphatase (PTPPase) was purified almost to homogeneity from rat brain, with [32P]p130gag-fps, an oncogene product of Fujinami sarcoma virus, as substrate. The characteristics of the purified preparation of PTPPase were as follows: the enzyme was a monomer with a molecular mass of 23 kDa; its optimum pH was 5.0-5.5; its activity was not dependent on bivalent cations; its activity was strongly inhibited by sodium vanadate, but was not inhibited by ZnCl2, L(+)-tartrate or NaF; it catalysed the dephosphorylation of [32P]p130gag-fps, [[32P]Tyr]casein, p-nitrophenyl phosphate and L-phosphotyrosine, but did not hydrolyse [[32P]Ser]tubulin, L-phosphoserine, DL-phosphothreonine, 5′-AMP, 2′-AMP or beta-glycerophosphate significantly. During the purification, most of the PTPPase activity was recovered in distinct fractions from those of conventional low-molecular-mass acid phosphatase (APase), which was reported to be a major PTPPase [Chernoff & Li (1985) Arch. Biochem. Biophys. 240, 135-145], from DE-52 DEAE-cellulose column chromatography, and those two enzymes could be completely separated by Sephadex G-75 column chromatography. APase also showed PTPPase activity with [32P]p130gag-fps, but the specific activity was lower than that of PTPPase with molecular mass of 23 kDa, and it was not sensitive to sodium vanadate. These findings suggested that PTPPase (23 kDa) was the major and specific PTPPase in the cell.


1983 ◽  
Vol 61 (7) ◽  
pp. 744-749 ◽  
Author(s):  
J. Downey ◽  
D. Mahan ◽  
T. G. Flynn ◽  
C. E. Bird ◽  
A. F. Clark

To further characterize the androgen dependence of prostatic acid phosphatase (AP), the isoelectric focusing patterns of enzyme activity have been examined for normal and castrated adult rats and for rats receiving androgen injections. Isoelectric focusing was performed in polyacrylamide gels over the pH range 4–8. Naphthyl phosphate was used as substrate for staining. For normal rats there was a single lysosomal band (isoelectric point (pI) = 7.35 ± 0.04), four closely migrating secretory bands (pI = 5.96–5.63), and an androgen-dependent band (pI = 6.37 ± 0.05) which as yet has not been identified as either lysosomal or secretory. Following castration the secretory bands decreased significantly in staining intensity, the androgen-dependent band disappeared, and two new lysosomal bands (pI's = 7.13 ± 0.03 and 7.00 ± 0.03) appeared. With androgen replacement the latter two bands disappeared, the androgen-dependent band reappeared, and the secretory bands increased in staining intensity but with the most anodic of the four appearing before the others. This suggests that it could be a precursor to the others. The isoelectric focusing patterns of AP activity appear to be a better method of assessing the androgen status of the prostate than are the previously used parameters, namely, enzyme specific activity, degree of inhibition by tartrate, and polyacrylamide gel electrophoretic pattern.


1972 ◽  
Vol 70 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Mario A. Pisarev ◽  
Noe Altschuler ◽  
Leslie J. DeGroot

ABSTRACT The process of secretion of the thyroid hormone involves several steps: pinocytosis of thyroglobulin, fusion of the colloid droplets with the lysosomes, digestion of thyroglobulin by a cathepsin, dehalogenation of tyrosines and release of thyronines into the blood stream. The present paper describes a double isotope technique for studying the first two steps. Thyrotrophin (TSH) administration to rats increased the radioactivity present in all fractions, specially in the 15 000 × g pellet. When the subcellular distribution of acid phosphatase was determined, the highest specific activity was found in this fraction, thus indicating the presence of lysosomes. The content of radioactive materials in the 15 000 × g pellet was analyzed by trichloroacetic acid precipitation and by ascending paper chromatography using n-butanol:ethanol:ammonium hydroxide (5:1:2;v/v) as solvent system. The results obtained showed that 90% of the radioactivity was protein bound and strongly suggest that this material is thyroglobulin.


2015 ◽  
Vol 26 (3) ◽  
pp. 495-505 ◽  
Author(s):  
Meredith O. Sweeney ◽  
Agnieszka Collins ◽  
Shae B. Padrick ◽  
Bruce L. Goode

Branched actin filament networks in cells are assembled through the combined activities of Arp2/3 complex and different WASP/WAVE proteins. Here we used TIRF and electron microscopy to directly compare for the first time the assembly kinetics and architectures of actin filament networks produced by Arp2/3 complex and dimerized VCA regions of WAVE1, WAVE2, or N-WASP. WAVE1 produced strikingly different networks from WAVE2 or N-WASP, which comprised unexpectedly short filaments. Further analysis showed that the WAVE1-specific activity stemmed from an inhibitory effect on filament elongation both in the presence and absence of Arp2/3 complex, which was observed even at low stoichiometries of WAVE1 to actin monomers, precluding an effect from monomer sequestration. Using a series of VCA chimeras, we mapped the elongation inhibitory effects of WAVE1 to its WH2 (“V”) domain. Further, mutating a single conserved lysine residue potently disrupted WAVE1's inhibitory effects. Taken together, our results show that WAVE1 has unique activities independent of Arp2/3 complex that can govern both the growth rates and architectures of actin filament networks. Such activities may underlie previously observed differences between the cellular functions of WAVE1 and WAVE2.


1972 ◽  
Vol 127 (1) ◽  
pp. 87-96 ◽  
Author(s):  
P. G. Bolton ◽  
A. C. R. Dean

1. Phosphatase synthesis was studied in Klebsiella aerogenes grown in a wide range of continuous-culture systems. 2. Maximum acid phosphatase synthesis was associated with nutrient-limited, particularly carbohydrate-limited, growth at a relatively low rate, glucose-limited cells exhibiting the highest activity. Compared with glucose as the carbon-limiting growth material, other sugars not only altered the activity but also changed the pH–activity profile of the enzyme(s). 3. The affinity of the acid phosphatase in glucose-limited cells towards p-nitrophenyl phosphate (Km 0.25–0.43mm) was similar to that of staphylococcal acid phosphatase but was ten times greater than that of the Escherichia coli enzyme. 4. PO43−-limitation derepressed alkaline phosphatase synthesis but the amounts of activity were largely independent of the carbon source used for growth. 5. The enzymes were further differentiated by the effect of adding inhibitors (F−, PO43−) and sugars to the reaction mixture during the assays. In particular, it was shown that adding glucose, but not other sugars, stimulated the rate of hydrolysis of p-nitrophenyl phosphate by the acid phosphatase in carbohydrate-limited cells at low pH values (<4.6) but inhibited it at high pH values (>4.6). Alkaline phosphatase activity was unaffected. 6. The function of phosphatases in general is discussed and possible mechanisms for the glucose effect are outlined.


2016 ◽  
Vol 26 (1) ◽  
pp. 15-23
Author(s):  
Saima Khan ◽  
Meenu Katoch ◽  
Sharada Mallubhotla ◽  
Suphla Gupta ◽  
Manju Sambyal ◽  
...  

The potential of various culture lines of Atropa acuminata were investigated for resourcing acid phosphatase (ACP) (3.1.3.2). Crude enzyme extract comprised of a mixture of four isoforms, distinguishable by polyacrylamide gel electrophoresis (PAGE) with molecular weight ranging from 39 to 215 kDa. In vitro regenerated proliferative shoots, callus and roots showed higher specific activity (2.49, 3.41, 2.91 U/mg protein, respectively) as compared to in vivo grown plants (0.71 U/mg protein). ACP activity in root cultures increased progressively up to 4.6 U/mg during the entire growth period (2 ? 24 weeks), whereas in case of shoot cultures, the specific activity escalated to 2.49 U/mg at 8 weeks, which then declined subsequently (1.95 U/mg). Similarly, callus cultures initially showed a higher phosphohydrolytic activity (3.41 U/mg protein) until 8 weeks by which period, it decreased with the passage of growth period. The present studies reveal an alternate system for resourcing of ACP from Atropa acuminata.Plant Tissue Cult. & Biotech. 26(1): 15-23, 2016 (June)


1979 ◽  
Vol 178 (3) ◽  
pp. 761-767 ◽  
Author(s):  
D B Lowrie ◽  
P W Andrew ◽  
T J Peters

Macrophages were obtained by pulmonary lavage from normal rabbits or rabbits that had developed pulmonary granulomas after receiving intravenous BCG vaccine 2-3 weeks earlier. The cells were disrupted in iso-osmotic sucrose and a low-speed supernatant was fractionated by isopycnic centrifugation on a linear sucrose density gradient. Three populations of hydrolase-containing granules (putative lysosomes) were found in both normal and BCG-induced macrophages. They were distinguished by their different distributions in the gradient and different sensitivities to disruption by digitonin and were termed:type A, containing lysozyme; type B, containing N-acetyl-beta-glucosaminidase, beta-glactosidase, beta-glucuronidase and possibly some lysozyme; type C, containing cathepsin D. Acid phosphatase appeared to be about equally distributed between type B and C granules. Type A and B granules from BCG-induced macrophages showed markedly greater equilibrium density than did those from normal macrophages. Beta-glucuronidase and acid phosphatase had greater specific activity in the induced cells.


2017 ◽  
Vol 975 ◽  
pp. 78-85 ◽  
Author(s):  
Samaneh Ahmadifar ◽  
Tien Canh Le ◽  
Lucia Marcocci ◽  
Paola Pietrangeli ◽  
Mircea Alexandru Mateescu

1978 ◽  
Vol 79 (1) ◽  
pp. 9-16 ◽  
Author(s):  
M. P. TENNISWOOD ◽  
PAMELA P. ABRAHAMS ◽  
C. E. BIRD ◽  
A. F. CLARK

Polyacrylamide gel electrophoresis of filtrates from adult rat prostatic tissue showed two bands of acid phosphatase activity. These corresponded to the lysosomal and secretory acid phosphatases. After castration the secretory acid phosphatase disappeared. The specific activity of the enzyme increased from the time of castration to a maximum on day 7 before declining steadily, while the percentage inhibition by tartrate of acid phosphatase increased from control levels to a maximum on day 7 and then decreased to a new steady state by day 15. When 5α-androstane-3β,17β-diol was administered i.p. at a dose of 2 mg/day, starting immediately after castration, the secretory acid phosphatase was retained but the percentage inhibition and the specific activity were both raised above control levels. When this steroid was administered daily starting 7 days after castration the secretory acid phosphatase band on the gels returned more rapidly than with the classical androgens, but the percentage inhibition and specific activity were once again raised. Intraperitoneal administration of 5β-dihydrotestosterone, at a dose of 2 mg/day, did not maintain the secretory acid phosphatase activity which disappeared by day 5. However, the specific activity of acid phosphatase and the percentage inhibition by tartrate were both raised throughout the experiment. If this steroid was given 7 days after castration, the percentage inhibition by tartrate did not respond and fell to the level seen in castrated rats. The specific activity, however, remained significantly above the level found in castrated control rats.


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