Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Outer-arm dynein purified from trout spermatozoa was disrupted by low-ionic-strength dialysis, and the resulting subunits were separated by sucrose density-gradient centrifugation. The intact 19 S dynein, containing the alpha- an beta-heavy chains, intermediate chains (ICs) 1-5 and light chains (LCs) 1-6, yielded several discrete particles: a 17.5 S adenosine triphosphatase (ATPase) composed of the alpha- and beta-chains ICs 3-5 and LC 1; a 9.5 S complex containing ICs 1 and 2 together with LCs 2, 3, 4, and 6; and a single light chain (LC 5), which sedimented at approximately 4 S. In some experiments, ICs 3-5 also separated from the heavy chain complex and were obtained as a distinct subunit. Further dissociation of the 17.5 S particle yielded a 13.1 S ATPase that contained the beta-heavy chain and ICs 3-5. The polypeptide compositions of the complexes provide new information on the intermolecular associations that occur within dynein. Substructural features of the trout dynein polypeptides also were examined. The heavy chains were subjected to vanadate-mediated photolysis at the V1 sites by irradiation at 365 nm in the presence of Mg2+, ATP, and vanadate. Fragment pairs of relative molecular mass (Mr) 245,000/185,000 and 245,000/170,000 were obtained from the alpha- and beta-heavy chains, respectively. Photolysis of these molecules at their V2 sites, by irradiation in the presence of vanadate and Mn2+, yielded fragments of Mr 160,000/270,000 and 165,000/250,000, respectively. These values confirm that the alpha- and beta-heavy chains have masses of 430,000 and 415,000 daltons, respectively. Immunological analysis using monoclonal antibodies revealed that one intermediate chain from trout dynein (IC 2) contains epitopes present in two different intermediate chains from Chlamydomonas dynein. This indicates that specific sequences within the dynein intermediate chains have been highly conserved throughout evolution.
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PMID:Outer-arm dynein from trout spermatozoa: substructural organization. 169 10

One hundred and five sexually mature male hamsters were divided in different groups. In the first experiment hamsters were administered gossypol, 10 mg/kg and 20 mg/kg/body weight/day, for twenty and thirty days. In the second experiment hamsters were administered gossypol, 5, 10 and 20 mg/kg/body weight/day, for sixty days. In the third experiment, hamsters were administered gossypol 5 mg, 10 mg, 20 mg and 40 mg/kg body weight/day for 45 days. Animals in all the groups were given gossypol by oral intubation every day. No significant effect on the body weight of hamsters following gossypol treatment was observed. At low doses the weights of testis and accessory sex organs were not statistically different from those of the controls. A significant decrease in testis and epididymis weight was however observed following high doses of gossypol. Low doses of gossypol treatment did not affect the motility of the vas deferens spermatozoa. The vas deferens spermatozoa were however immotile after 40 mg/kg/day gossypol treatment. Gossypol treatment induced a series of histological changes in the seminiferous epithelium of the hamster testis. The earliest sign of drug effect was seen in spermatids and with the increase in doses the effects became more pronounced and extended to the spermatocytes. At 40 mg/kg dose an almost complete arrest of spermatogenesis was observed. Quantitatively, the ratio of pachytene spermatocytes: resting spermatocytes and step 7 spermatids: pachytene spermatocytes decreased significantly. The step 7 spermatids did not mature to step 19 spermatids at all. Histochemically activities of ATPase, SDH and LDH decreased with the increasing doses of gossypol, the activity of 3B hydroxysteroid dehydrogenase was not affected by gossypol treatment. In testis the glucose-6-phosphatase activity was not affected significantly but the activities of fructose 1, 6-diphosphatase and glucose-6-phosphate isomerase decreased significantly with the increasing doses of gossypol. Amylase activity rose significantly at higher doses. Marked changes in LDH and LDH-X were however observed with the increase in gossypol dose. In liver the activity of glucose-6-phosphatase increased significantly while the activities of fructose 1, 6-diphosphatase, glucose-6-phosphate isomerase and amylase were not affected following gossypol treatment. The glycogen contents however increased significantly following high doses of gossypol. No changes in testosterone production and plasma levels of testosterone were observed following gossypol treatment.
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PMID:Response of hamster to the antifertility effect of gossypol. 170 27

The goat spermatozoa membranes isolated after treatment with octa (ethylene glycol) mono n-dodecyl ether (C12E8) followed by discontinuous sucrose density gradient centrifugation have been found to contain an ATPase that is stimulated by externally added Ca2+ only. The membrane fraction has also found to contain Mg(2+)-dependent Ca(2+)-ATPase activity, however the former activity is about 2 fold higher than the latter. The molecular weight of the enzyme is found to be about 97,000 on SDS-polyacrylamide gel. The optimum concentration of Ca2+ required for maximum activity is 3 mM for both Mg(2+)-dependent and Mg(2+)-independent Ca(2+)-ATPase. Histidine and imidazole buffers are found to be the most suitable for dependent and independent enzyme activities respectively. ATP with an optimum concentration of 4 mM is observed to be the best substrate than any other nucleotides. The inhibitors like trifluoperazine and vanadate and group specific probes e.g. DTNB and TNBS inhibit these two enzymes but at different rates. Ca(2+)-uptake study shows that the uptake in the presence of Ca2+ and ATP is higher than in the presence of Mg2+, Ca2+ and ATP. The findings lead us to believe that the Mg(2+)-independent Ca(2+)-ATPase has some role in Ca2+ transport like Mg(2+)-dependent enzyme.
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PMID:Biochemical characterization of a calcium ion stimulated-ATPase from goat spermatozoa. 183 Jan 26

The 'motor' proteins of eukaryotic cells contain specialized domains that hydrolyse ATP to produce force and movement along a cytoskeletal polymer (actin in the case of the myosin family; microtubules in the case of the kinesin family and dyneins). There are motor-protein superfamilies in which each member has a conserved force-generating domain joined to a different 'tail' which conveys specific attachment properties. The minus-end-directed microtubule motors, the dyneins, may also constitute a superfamily of force-generating proteins with distinct attachment domains. Axonemal outer-arm dynein from sea urchin spermatozoa is a multimeric protein consisting of two heavy chains (alpha and beta) with ATPase activity, three intermediate chains and several light chains. Here I report the sequence of cloned complementary DNA encoding the beta heavy chain of a dynein motor molecule. The predicted amino-acid sequence reveals four ATP-binding consensus sequences in the central domain. The dynein beta heavy chain is thought to associate transiently with a microtubule during ATP hydrolysis, but the ATP-dependent microtubule-binding sequence common to the kinesin superfamily is not found in the dynein beta heavy chain. These unique features distinguish the dynein beta heavy chain from other motor protein superfamilies and may be characteristic of the dynein superfamily.
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PMID:Four ATP-binding sites in the midregion of the beta heavy chain of dynein. 183 Sep 24

The motility of fowl spermatozoa at various temperatures was shown to be a function of their intracellular calcium content, measured after hypotonic lysis of the cells. Retention of calcium by spermatozoa, with consequent enhancement of motility, increased as the temperature was lowered from 40 degrees to 30 degrees C. Raising the temperature within this range subsequently reduced calcium retention and motility again. The temperature-dependent retention of calcium was a function of the rate of calcium efflux rather then influx. The temperature-sensitive efflux mechanism appeared to involve a Ca2+ ATPase which was relatively inactive at 30 degrees C, but active at 40 degrees C.
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PMID:Temperature-mediated regulation of calcium flux and motility in fowl spermatozoa. 183 68

An enriched plasma membrane fraction was isolated from caput, corpus, and cauda rat spermatozoa and analyzed for lipid and protein content, thermal phase transition temperature using electron paramagnetic resonance spectroscopy (EPR), and enzymatic assays of calcium-dependent ATPase activity. Based on sperm concentration, total membrane phospholipid, cholesterol, and protein content declined as sperm passed through the epididymis. A more refined analysis of the bulk plasma membrane phospholipid revealed that approximately 56% of the phospholipid consisted of choline (PC) and ethanolamine (PE) phosphoglycerides; the remainder consisted of sphingomyelin (SM), phosphatidylserine (PS), and diphosphatidylglycerol (DPG). The mole percent of PE increased in sperm proceeding from the caput to the corpus epididymis and then declined from the corpus to the cauda epididymis. The phospholipid-bound fatty acids consisted primarily of palmitate (C16:0) and stearate (C18:0), with a significant increase in the mole percent of the docosapentenoyl acyl group (C22:5) in cauda sperm. Arrhenius' plots of the EPR peak height signals using the lipid soluble spin label, 5-doxyldecane, and the calcium-dependent ATPase activity as a function of temperature demonstrated a change in the apparent fluidity of the membrane and energy of activation of the calcium-dependent ATPase associated with the three sperm membrane preparations. These data suggest that the apparent fluidity and biochemical composition of the sperm membrane change during epididymal maturation.
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PMID:Correlation between changes in rat sperm membrane lipids, protein, and the membrane physical state during epididymal maturation. 184 30

The presence, distribution, and levels of phospholipase A2 and ATPases activities in those structures of the guinea pig spermatozoa that participate in the acrosome reaction were studied, both before and after capacitation, as well as during the acrosome reaction induced in vitro. Spermatozoa were collected from the cauda epididymis and incubated in the absence and presence of 1.15 mmol/L calcium, with and without the addition of 1 mumol/L A23187. Membrane fractions were recovered by vortexing and discontinuous sucrose density gradient centrifugation. Most of the Na+, K(+)-ATPase was recovered in the acrosome-free spermatozoa, but a clear, distinct presence of this enzyme was observed in the plasma membrane (25 against 101 nmoles Pi released per milligram of protein, respectively). The activity of this enzyme in the periacrosomal plasma and in the outer acrosomal membrane increased during calcium incubation. Ca2(+)-dependent ATPase was found in both membrane fractions, being higher in the periacrosomal plasma membrane. The addition of calcium induced a significant inhibition of this acrosomal ATPase, whereas the activity in the acrosome-free spermatozoa increased. The activity of phospholipase A2, under all experimental conditions, was found to be restricted to the soluble fraction.
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PMID:Subcellular distribution of phospholipase A2 and ATPases during capacitation and acrosome reaction in guinea pig spermatozoa. 185 52

In order to elucidate the biochemical mechanism of sperm capacitation, the relationship between plasmalemma Na,K-ATPase, capacitation and acrosome reaction was investigated. Plasmalemma of guinea pig spermatozoa was isolated by sucrose gradient centrifugation for the determination of Na,K-ATPase activity. As far as the authors are aware, the Na,K-ATPase activity in plasmalemma of the guinea pig has never been detected. By treating sperm plasmalemma with 0.05% DOC (deoxycholate), enzyme activity could be quantitatively measured. After spermatozoa were incubated in capacitation medium for 8 h, Na,K-ATPase activity was found to be decreased to 35.6% as compared with that before incubation. The spermatozoa incubated for 10.5 h in capacitation medium containing 1 and 5 mumol/L ouabain showed 46.5% and 64.4% acrosome reactions respectively, while the acrosome reaction of the control group was only 27.4%. The above results suggest that the decrease in the Na,K-ATPase activity of guinea pig spermatozoa may be a prerequisite for capacitation. Experimental results demonstrated for the first time that Na,K-ATPase activity exists in the sperm plasmalemma of the guinea pig. It was further found that the decrease of Na,K-ATPase activity of plasmalemma enhances sperm capacitation. It is suggested that sperm capacitation in the guinea pig is possibly induced by the decrease in plasmalemma Na,K-ATPase and, as a consequence, the intracellular Na+ is increased, which would benefit the exchange of Na+out/Ca++in and the onset of acrosome reaction.
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PMID:Studies on relationship between Na,K-ATPase activity and sperm capacitation in guinea pig. 196 23

1. At 40 degrees C, around the normal avian body temperature, demembranated fowl spermatozoa with no addition of monovalent chlorides were immotile. 2. Demembranated spermatozoa become motile at 40 degrees C when 0.1-0.5 M concentrations of NH4Cl, NaCl and KCl were added to the reactivation medium, with maximum motility occurring at 0.2-0.3 M in all cases. 3. The addition of NH4Cl, NaCl and KCl also stimulated the ATPase activity of crude dynein extract. In contrast, LiCl did not appreciably affect motility and ATPase activity. 4. These results showed that the flagellar dynein ATPase activity of fowl spermatozoa could be stimulated by the addition of certain monovalent chlorides, except LiCl, and demembranated spermatozoa might be motile at 40 degrees C.
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PMID:Activation of dynein adenosine triphosphatase and flagellar motility of demembranated spermatozoa by monovalent salts at 40 degrees C in the domestic fowl, Gallus domesticus. 197 31

The triple ATPase activities of washed spermatozoa of oligoasthenospermic men (but not of normals) were enhanced by the addition of caffeine and theophylline, which are known to have a stimulating effect on sperm motility. The biochemical mechanism of action of caffeine and theophylline on sperm homeostasis is discussed.
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PMID:The effects of caffeine and theophylline on the triple adenosine triphosphatase enzyme activities of spermatozoa from males with oligoasthenospermia. 213 54


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