Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the present investigation the results of a lead salt technique and two calcium salt techniques for the deomonstration of the activity of myosin adenosine triphosphatase in sections of both normal and pathological human skeletal muscle specimens are compared. It was seen that the histochemical results obtained by the different techniques are similar, especially with regard to the identification of fibre-types. It can be clearly stated, that the alkaline phosphatase activity present in muscle fibers of diseased skeletal msucles revealed only a very slight activity with the substrate ATP, so the alkaline phosphatase activity in general did not disturb the reliability of the different myosin ATPase techniques. Moreover it was found that the presence of the mitochondrial Ca2+ -ion activated ATPase with a high pH-optimum in muscle fibers did not give rise to faulty results. From studies with dinitrophenol it can be concluded that this substance activates the myosin ATPase present in type I fibres especially.
...
PMID:The value of enzyme histochemical techniques in the classification of fibre types of human skeletal muscle. 2. The histochemical demonstration of myosin adenosine triphosphatase in skeletal muscles from adult patients with or with no diseases of the neuromuscular system. A comparison between results obtained by calcium salt and lead salt techniques. 14 Aug 52

One of the low molecular weight components of myosin, g2, was isolated by alkali treatment of myosin and was chemically modified with a spin label reagent, 4-maleimido-2,2,6,6-tetramethylpiperidinooxyl. The label on g2 showed a rather weakly immobilized ESR spectrum and it was clearly affected by Ca2+; the half-maximal change was at around pCa 4. The spin-labeled g2 was incorporated into myosin by exchange with the intrinsic g2 of myosin in 0.6 M KSCN or 4 M LiC1. The label on g2 became strongly immobilized on association with myosin. Under the conditions used, ESR spectral change due to Ca2+ occurred at two different concentration ranges, which were as low as pCa 8 and at around pCa 4. Phosphorylated g2 was isolated from myosin after the protein kinase [EC 2.1.1.37]-catalyzed phosphorylation of myosin and it was also modified with the maleimide label. Dephosphorylation of the phosphorylated g2 was performed using E. coli alkaline phosphatase [EC 3.1.3.1]. The effects of Ca2+ on the ESR spectra of phosphorylated and dephosphorylated g2 were investigated on the state associated with myosin. A change in the ESR spectrum from strongly immobilized to weakly immobilized states was observed with both g2 chains on the addition of Ca2+. However, the effective concentration ranges of Ca2+ were quite different; around pCa 4 for the phosphorylated g2 and around pCa 8 for the dephosphorylated g2. The results indicate that g2 undergoes a conformational change at physiological levels of Ca2+ sufficient to saturate troponin, but it does not do so after phosphorylation.
...
PMID:Ca2+-induced conformational changes of spin-labeled g2 chain bound to myosin and the effect of phosphorylation. 18 78

The histochemical demonstration of alkaline phosphatase (AP) activity and localization of smooth muscle myosin (SMM), F-actin, and desmin were carried out on frozen sections of testes and ovaries from 15-day-old fetal to newborn rats. The presence of immunocytochemically localized SMM and desmin was confirmed by Western blot analysis of proteins from isolated gonads. The development of smooth muscle cells was predominant in the testis. The first SMM-positive cells with an increasing intensity for F-actin and desmin appeared in the testicular tunica albuginea and around the testicular cords by the age of 16 days. A continuous layer of SMM- and F-actin-positive (but not uniformly desmin-positive) myoid cells was detected in the newborn testis. In the early gonads and in the newborn ovary, a majority of the interstitial cells expressed desmin, indicating that, in undifferentiated tissues, non-myogenic cells may also express desmin. During fetal development, male and female gonocytes showed a decrease in F-actin content but retained their high AP activity. In the cortex of the newborn rat ovary, the observed high AP activity and the presence of desmin may be associated with the postnatal histogenesis of the follicles. The presence of SMM-containing cells in the hilus of the ovary may be required for the demarcation of the ovary from the mesonephros by the constriction of the mesovarium. The occurrence of SMM-positive cells predominantly in male fetuses suggests that the development of the contractile cells in the fetal testis may be induced by testicular androgens.
...
PMID:Differentiation of smooth muscle cells in the fetal rat testis and ovary: localization of alkaline phosphatase, smooth muscle myosin, F-actin, and desmin. 162 8

mAbs specific for calmodulin were used to examine the distribution of calmodulin in vegetative Dictyostelium cells. Indirect immunofluorescence indicated that calmodulin was greatly enriched at the periphery of phase lucent vacuoles. The presence of these vacuoles in newly germinated (non-feeding) as well as growing cells, and the response of the vacuoles to changes in the osmotic environment, identified them as contractile vacuoles, osmoregulatory organelles. No evidence was found for an association of calmodulin with endosomes or lysosomes, nor was calmodulin enriched along cytoskeletal filaments. When membranes from Dictyostelium cells were fractionated on equilibrium sucrose density gradients, calmodulin cofractionated with alkaline phosphatase, a cytochemical marker for contractile vacuole membranes, at a density of 1.156 g/ml. Several high molecular weight calmodulin-binding proteins were enriched in the same region of the gradient. One of the calmodulin-binding polypeptides (molecular mass approximately 150 kD) cross-reacted with an antiserum specific for Acanthamoeba myosin IC. By indirect immunofluorescence, this protein was also enriched on contractile vacuole membranes. These results suggest that a calmodulin-binding unconventional myosin is associated with contractile vacuoles in Dictyostelium; similar proteins in yeast and mammalian cells have been implicated in vesicle movement.
...
PMID:Association of calmodulin and an unconventional myosin with the contractile vacuole complex of Dictyostelium discoideum. 162 38

Histogenesis of pleomorphic adenomas was investigated by histological and electron microscopical methods. Histochemically alkaline phosphatase activity was revealed in transformed cells. Positive immunohistochemical reaction was shown in cells of pleomorphic adenomas with polyclonal antibodies against the smooth muscle myosin, human carbonic anhydrase III and monoclonal antibodies to cytokeratins N8, N17, N18, vimentin (clone NT-30) and to membrane epithelial antigen. It is concluded that these tumours are of the epithelial nature.
...
PMID:[Histogenesis of pleomorphic adenomas of the salivary glands]. 171 11

The appearance of myosin isoforms in skeletal muscles of turkey embryos, poults, and toms was studied, using monoclonal antibodies raised against myosin isoforms in chicken fast-twitch muscle (Pectoralis). The myosin extract was prepared by repeated salt extraction-precipitation. The reactivity of monoclonal antibodies with turkey myosin isoforms was tested by an enzyme linked immunosorbent assay using alkaline phosphatase-conjugated antibody and detection by color development with p-nitrophenyl phosphate. Detection was also effected by protein slot blotting using peroxidase-conjugated antibody and color development with 3,3'-diaminobenzidine tetrahydrochloride. The monoclonal antibody AB8 was found to be specific for the adult myosin isoform, present in Pectoralis muscle of 14-day-old and adult turkeys and adult chickens. Subsequent peptide mapping also indicated that the adult myosin isoform of turkey Pectoralis muscle was nearly identical to the adult isoform from chickens. The monoclonal antibody 2E9 reacted with the myosin extract only from poults at ages of 7 days and 14 days posthatch, indicating that 2E9 is specific for the neonatal myosin isoform. The reactivity of 2E9 was noted with the muscle of the mixed fiber type (the thigh muscle group) as well as with the fast-twitch muscle (Pectoralis). Monoclonal antibodies EB 165 and AG6 were found to react with the myosin extract from all ages tested. Based on the reactivity with monoclonal antibodies, it was concluded that myosin in turkey muscles existed as at least three discrete isoforms that were expressed sequentially in the course of muscle development.
...
PMID:Myosin isoform expression in skeletal muscles of turkeys at various ages. 192 93

The active-site topology of smooth muscle myosin has been investigated by direct photoaffinity-labeling studies with [3H]ADP. Addition of vanadate (Vi) and Co2+ enabled [3H]ADP to be stably trapped at the active site (t1/2 greater than 5 days at 0 degrees C). The extraordinary stability of the myosin.Co2+.[3H]ADP.Vi complex allowed it to be purified free of excess [3H]ADP before irradiation began and ensured that only active-site residues became labeled. Following UV irradiation, approximately 10% of the trapped [3H]ADP became covalently attached at the active site. All of the [3H]ADP incorporated into the 200-kDa heavy chain, confirming earlier results using untrapped [alpha-32P]ATP [Maruta, H., & Korn, E. (1981) J. Biol. Chem. 256, 499-502]. After extensive trypsin digestion of labeled subfragment 1, HPLC separation methods combined with alkaline phosphatase treatment allowed two labeled peptides to be isolated. Sequence analysis of both labeled peptides indicated that Glu-185 was the labeled residue. Since Glu-185 has been previously identified as a residue at the active site of smooth myosin using [3H]UDP as a photolabel [Garabedian, T. E., & Yount, R. G. (1990) J. Biol. Chem. 265, 22547-22553], these results provide further evidence that Glu-185, located immediately adjacent to the glycine-rich loop, is located in the purine binding pocket of the active site of smooth muscle myosin.
...
PMID:Direct photoaffinity labeling of gizzard myosin with vanadate-trapped adenosine diphosphate. 193 44

The active site of chicken gizzard myosin was labeled by direct photoaffinity labeling with [3H]UDP. [3H] UDP was stably trapped at the active site by addition of vanadate (Vi) and Co2+. The extraordinary stability of the myosin.Co2+.[3H]UDP.Vi complex (t1/2 greater than 5 days at 0 degrees C) allowed it to be purified free of extraneous [3H]UDP before irradiation began. Upon UV irradiation, greater than 60% of the trapped [3H]UDP was photoincorporated into the active site. Only the 200-kDa heavy chain was labeled, confirming earlier results (Maruta, H., and Korn, E. (1981) J. Biol. Chem. 256, 499-502) using [3H]UTP. Extensive tryptic digestion of photolabeled myosin subfragment 1 followed by high performance liquid chromatography separations and removal of nucleotide phosphates by treatment with alkaline phosphatase allowed two labeled peptides to be isolated. Sequencing of the labeled peptides and radioactive counting showed that Glu185 was the residue labeled. Since UDP is a "zero-length" cross-linker, Glu185 is located at the purine-binding pocket of the active site of smooth myosin and adjacent to the glycine-rich loop which binds the polyphosphate portion of ATP. This Glu residue is conserved in smooth and nonmuscle myosins and is the same residue identified previously by [3H]UTP photolabeling in Acanthamoeba myosin II (Atkinson, M. A., Robinson, E. A., Appella, E., and Korn, E. D. (1986) J. Biol. Chem. 261, 1844-1848).
...
PMID:Direct photoaffinity labeling of gizzard myosin with [3H]uridine diphosphate places Glu185 of the heavy chain at the active site. 197 81

Various chromogen protocols for visualizing peroxidase and alkaline phosphatase activity in immunoenzyme histochemistry were compared with respect to their sensitivity. They were tested on tissue sections of human skeletal muscle and in an antigen spot test using antibodies against slow skeletal muscle myosin. The chromogens included 3-amino-9-ethylcarbazole (AEC), 3, 3'-diaminobenzidine (DAB), p-phenylenediamine-pyrocatechol (PPD-PC) and 4-chloro-1-naphthol (CN) in peroxidase histochemistry, and 5-bromo-4-chloro-3-indolyl phosphate-nitro blue tetrazolium salt (BCIP-NBT), BCIP-tetra nitro blue tetrazolium salt (TNBT) and various combinations of substituted naphthol phosphate-diazonium salt in alkaline phosphatase histochemistry. DAB, CN, and PPD-PC were also employed with imidazole and DAB in addition to Co2+ and Ni2+ ions. The results indicate that DAB-imidazole and DAB-Co2+ and Ni2+ ions are the most sensitive chromogen protocols for visualizing peroxidase activity. Although no large differences were found between the various chromogen protocols for visualizing alkaline phosphatase activity, the protocol BCIP-TNBT is especially recommended. Furthermore, the various chromogen protocols were evaluated as to stability of chromogen solutions and final precipitates, background staining, localization properties, and enhancement of enzyme activity.
...
PMID:Sensitivity of various visualization methods for peroxidase and alkaline phosphatase activity in immunoenzyme histochemistry. 241 13

Phosphorylated rabbit cardiac alpha alpha-tropomyosin has been prepared either enzymatically (Montgomery, K., and Mak, A.S. (1984) J. Biol. Chem. 259, 5555-5560) or by fractionation of the phosphorylated and nonphosphorylated forms on a Mono Q column in 9 M urea, 50 mM Tris, pH 8.0. Although the phosphorylated and nonphosphorylated forms showed no difference in their F-actin binding properties, the phosphorylated protein had substantially higher viscosities at low ionic strengths, indicating a greater propensity for head-to-tail interaction. Similar measurements showed the strengthening of this interaction by whole troponin to be substantially reduced by phosphorylation even though the binding of whole troponin and troponin T to tropomyosin was demonstrated by affinity chromatography to be, if anything, strengthened by phosphorylation. In a reconstituted actin (4 microM) plus myosin subfragment 1 ATPase assay (50 mM ionic strength), significantly higher activities over a range (1 to 8 microM) of subfragment 1 concentrations were observed with phosphorylated tropomyosin compared with the nonphosphorylated protein. In the fully reconstituted system with troponin, there was no significant difference in the inhibition of ATPase in the absence of Ca2+. However, in its presence, the activities were appreciably increased with the phosphorylated tropomyosin compared to those with the nonphosphorylated form. These differences were eliminated by treatment of the phosphorylated tropomyosin with alkaline phosphatase. This is the first demonstration of an effect of phosphorylation on the functional properties of tropomyosin.
...
PMID:Effect of phosphorylation on the interaction and functional properties of rabbit striated muscle alpha alpha-tropomyosin. 252 28


1 2 3 4 5 Next >>

---