The activity for the induction of the sperm acrosome reaction localises in the outer layers and exists in the high-molecular-weight components of the egg-jelly of the newt, Cynops pyrrhogaster

Zygote ◽  
2002 ◽  
Vol 10 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Takayuki Sasaki ◽  
Saori Kamimura ◽  
Hiroyuki Takai ◽  
Akihiko Watanabe ◽  
Kazuo Otinake

Localisation of the acrosome reaction inducing activity in egg-jelly was examined in the newt, Cynops pyrrhogaster. The jelly has six layers: the J0, J1, J2, J3, J4 and st layers. Jelly was mechanically dissected and placed on a Millipore filter. When sperm were added from the outer surface side of the jelly, most of them exhibited the acrosome reaction after passing through the jelly. When egg-jelly was divided into four layers, strong activity for the induction of acrosome reaction was detected in the outer layers, J4+st. These findings suggest that the acrosome reaction is induced by a substance in the outer layers of the egg-jelly. Among jelly components separated by SDS-PAGE, a fraction of more than 500 kDa in molecular weight induced the acrosome reaction. Wheat germ agglutinin (WGA), Griffonia simplicifoliar agglutinin 1 (GS-1), Maclura pomifera agglutinin (MPA) and Arachis hypogaea agglutinin (PNA) inhibited the induction of the acrosome reaction by jelly extract, and WGA did so in a dose-dependent manner. Those lectins precipitated some molecules of over 500 kDa. These results suggest that the acrosome reaction is induced by the high molecular-weight components of egg-jelly in C. pyrrhogaster.

1990 ◽  
Vol 63 (03) ◽  
pp. 505-509 ◽  
Author(s):  
Thomas Mätzsch ◽  
David Bergqvist ◽  
Ulla Hedner ◽  
Bo Nilsson ◽  
Per Østergaar

SummaryA comparison between the effect of low molecular weight heparin (LMWH) and unfragmented heparin (UH) on induction of osteoporosis was made in 60 rats treated with either UH (2 IU/ g b w), LMWH in 2 doses (2 Xal U/g or 0.4 Xal U/g) or placebo (saline) for 34 days. Studied variables were: bone mineral mass in femora; fragility of humera; zinc and calcium levels in serum and bone ash and albumin in plasma. A significant reduction in bone mineral mass was found in all heparin-treated rats. There was no difference between UH and LMWH in this respect. The effect was dose-dependent in LMWH-treated animals. The zinc contents in bone ash were decreased in all heparin-treated rats as compared with controls. No recognizable pattern was seen in alterations of zinc or calcium in serum. The fragility of the humera, tested as breaking strength did not differ between treatment groups and controls. In conclusion, if dosed according to similar factor Xa inhibitory activities, LMWH induces osteoporosis to the same extent as UH and in a dose-dependent manner. The zinc content in bone ash was decreased after heparin treatment, irrespective of type of heparin given.


1993 ◽  
Vol 71 (9-10) ◽  
pp. 488-500 ◽  
Author(s):  
Valerie M. Weaver ◽  
Boleslaw Lach ◽  
P. Roy Walker ◽  
Marianna Sikorska

Three chemically distinct serine, but not cysteine, protease inhibitors (phenylmethylsulphonyl fluoride, N-tosyl-L-phenylalanylchloromethyl ketone and 3,4-dichloroisocoumarin) prevented, in a dose-dependent manner, the characteristic apoptotic internucleosomal DNA cleavage (DNA ladder) typically observed in thymocytes in response to dexamethasone and teniposide VM-26. This effect was not the result of a direct inhibition of the Ca2+, Mg2+-dependent endonuclease, since oligonucleosomal DNA cleavage occurred in the presence of these inhibitors in isolated nuclei. The proteolytic step occurred at a very early stage of apoptosis, and preincubation of thymocytes with the inhibitors before dexamethasone or teniposide VM-26 were added irreversibly suppressed ladder formation. This implied that the cellular effector(s) of these compounds preexisted and were not resynthesized in response to the inducers of apoptosis. Serine protease inhibitors also suppressed apoptotic cell shrinkage and complete nuclear collapse, suggesting that these morphological changes were directly related to internucleosomal fragmentation of DNA. However, the serine protease inhibitors did not prevent high molecular weight DNA cleavage (> 50 kilobases) that preceded the ladder formation and thymocytes still died by apoptosis. This supported the view that internucleosomal DNA cleavage, considered to be the biochemical marker of apoptosis, might in fact be a late and dispensable step and that the newly described high molecular weight DNA cleavage might be a better indicator of apoptosis.Key words: serine protease, apoptosis, internucleosomal DNA fragmentation, high molecular weight DNA cleavage, protease inhibitors.


Blood ◽  
1991 ◽  
Vol 77 (3) ◽  
pp. 500-507 ◽  
Author(s):  
RN Puri ◽  
F Zhou ◽  
CJ Hu ◽  
RF Colman ◽  
RW Colman

In this study we show that high molecular weight kininogen (HK) inhibited alpha-thrombin-induced aggregation of human platelets in a dose-dependent manner with complete inhibition occurring at plasma concentration (0.67 mumol/L) of HK. HK (0.67 mumol/L) also completely inhibited thrombin-induced cleavage of aggregin (Mr = 100 Kd), a surface membrane protein that mediates adenosine diphosphate (ADP)- induced shape change, aggregation, and fibrinogen binding. The inhibition of HK was specific for alpha- and gamma-thrombin-induced platelet aggregation, because HK did not inhibit platelet aggregation induced by ADP, collagen, calcium ionophore (A23187), phorbol myristate acetate (PMA), PMA + A23187, or 9,11-methano derivative of prostaglandin H2 (U46619). These effects were explained by the ability of HK, at physiologic concentration, to completely inhibit binding of 125I-alpha-thrombin to washed platelets. As a result of this action of HK, this plasma protein also completely inhibited thrombin-induced secretion of adenosine triphosphate, blocked intracellular rise in Ca2+ in platelets exposed to alpha- and gamma-thrombin, inhibited thrombin- induced platelet shape change, and blocked the ability of thrombin to antagonize the increase in intracellular cyclic adenosine monophosphate (cAMP) levels induced by iloprost. Because elevation of cAMP is known to inhibit binding of thrombin to platelets, we established that HK did not increase the intracellular concentration of platelet cAMP. Finally, HK did not inhibit enzymatic activity of thrombin. To study the role of HK in the plasma environment, we used gamma-thrombin to avoid fibrin formation by alpha-thrombin. Platelet aggregation induced by gamma- thrombin was also inhibited by HK in a dose-dependent manner. The EC50 (concentration to produce 50% of the maximum rate of aggregation) of gamma-thrombin for washed platelets was 7 nmol/L and increased to 102 nmol/L when platelets were suspended in normal human plasma. The EC50 for platelet aggregation induced by alpha-thrombin in plasma deficient in total kininogen was 40 nmol/L. When supplemented with HK at plasma concentration (0.67 mumol/L), the EC50 increased to 90 nmol/L, a value similar to that for normal human plasma. These results indicate that (1) HK inhibits thrombin-induced platelet aggregation and cleavage of aggregin by inhibiting binding of thrombin to platelets; (2) HK is a specific inhibitor of platelet aggregation induced by alpha- and gamma- thrombin; and (3) HK plays a role in modulating platelet aggregation stimulated by alpha-thrombin in plasma.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
A. S. Zarena ◽  
Shubha Gopal ◽  
R. Vineeth

In the present study a protein termed agathi leaf protein (ALP) fromSesbania grandiflora Linn. (agathi) leaves was isolated after successive precipitation with 65% ammonium sulphate followed by purification on Sephadex G 75. The column chromatography of the crude protein resulted in four peaks of which Peak I (P I) showed maximum inhibition activity against hydroxyl radical. SDS-PAGE analysis of P I indicated that the molecular weight of the protein is≈29 kDa. The purity of the protein was 98.4% as determined by RP-HPLC and showed a single peak with a retention time of 19.9 min. ALP was able to reduce oxidative damage by scavenging lipid peroxidation against erythrocyte ghost (85.50 ± 6.25%), linolenic acid (87.67 ± 3.14%) at 4.33 μM, ABTS anion (88 ± 3.22%), and DNA damage (83 ± 4.20%) at 3.44 μM in a dose-dependent manner. The purified protein offered significant protection to lymphocyte (72% at 30 min) induced damage by t-BOOH. In addition, ALP showed strong antibacterial activity againstPseudomonas aeruginosa(20 ± 3.64 mm) andStaphylococcus aureus(19 ± 1.53 mm) at 200 μg/mL. The safety assessment showed that ALP does not induce cytotoxicity towards human lymphocyte at the tested concentration of 0.8 mg/mL.


1993 ◽  
Vol 128 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Nobuyoshi Kokawa ◽  
Mareo Yamoto ◽  
Kenichi Furukawa ◽  
Ryosuke Nakano

We performed partial purification of low molecular weight luteinizing hormone binding inhibitor from porcine follicular fluids and examined its biological activities. Following ultrafiltration, gel filtration and anion exchange of the pooled porcine follicular fluids, low molecular weight fractions (500–10,000 MW) inhibited [125I]hLH binding to porcine granulosa cells in a dose-dependent manner. The binding inhibition kinetics study revealed that the luteinizing hormone binding inhibitor may indicate a non-competitive inhibition with [125I]hLH binding. In vitro bioassay using adult mouse testicular interstitial cells revealed that the partially purified luteinizing hormone binding inhibitor reduced ovine LH-stimulated testosterone and cAMP production in a dose-dependent manner, whereas the luteinizing hormone binding inhibitor did not affect basal production of testosterone and cAMP. The inhibitory activity was heat stable and did not disappear with activated charcoal adsorption. The results of the present study suggest that the luteinizing hormone binding inhibitor may play an important role as an ovarian non-steroidal regulator modulating the receptor binding of LH and LH-mediated steroidogenesis.


1987 ◽  
Author(s):  
N A Booth ◽  
A Reith ◽  
B Bennett

Normal vascular endothelium and platelet α-granules contain an inhibitor of plasminogen activator (PAI-1) of about 48000 molecular weight, which is released by stimuli such as thrombin. An immunologically distinct inhibitor (PAI-2) of about 47000 molecular weight has been purified from placenta and from a histiocytic cell line U-937. The level of PA-inhibition in plasma is raised in late pregnancy and this may be due to increases in PAI-1 or in PAI-2 or in both.Using SDS-PAGE and zymography on fibrin/plasminogen /u-PA detector gels, we have found that normal plasma contains a band of inhibition of apparent molecular weight 40000, which can be neutralised by antiserum raised against PAI-1. Pregnancy plasma contained this band as well as additional inhibitor bands of apparent molecular weights 75000 and 130000. The novel high molecular weight PA-inhibitors were detectable by zymography at about 12 weeks gestation. They were specific for plasminogen activator and did not inhibit plasmin. They were inhibited by antiserum raised against PAI-2 from U-937 cells (a gift from Dr EKO Kruithof) and thus are immunologically related to PAI-2. They may represent circulating complexes of PAI-2 with another protein or aggregates of PAI-2, which retain inhibitory activity after SDS-PAGE. PAI-2 appears to represent a pregnancy associated protein that circulates in a number of different molecular weight forms.


Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 755 ◽  
Author(s):  
Alvarez ◽  
Guzmán

Club wheat (Triticum aestivum L. ssp. compactum (Host) Mackey), macha wheat (T. aestivum L. ssp. macha (Dekapr. & A.M. Menabde) Mackey) and Indian dwarf wheat (T. aestivum L. ssp. sphaerococcum (Percival) Mackey) are three neglected or underutilized subspecies of hexaploid wheat. These materials were and are used to elaborate modern and traditional products, and they could be useful in the revival of traditional foods. Gluten proteins are the main grain components defining end-use quality. The high molecular weight glutenin subunit compositions of 55 accessions of club wheat, 29 accessions of macha wheat, and 26 accessions of Indian dwarf wheat were analyzed using SDS-PAGE. Three alleles for the Glu-A1 locus, 15 for Glu-B1 (four not previously described), and four for Glu-D1 were detected. Their polymorphisms could be a source of genes for quality improvement in common wheat, which would permit both their recovery as new crops and development of modern cultivars with similar quality characteristics but better agronomic traits.


Reproduction ◽  
2004 ◽  
Vol 128 (6) ◽  
pp. 783-787 ◽  
Author(s):  
K Ashizawa ◽  
G J Wishart ◽  
A R A H Ranasinghe ◽  
S Katayama ◽  
Y Tsuzuki

The motility and acrosomal integrity of fowl spermatozoa in TES/NaCl buffer, with or without homogenized inner perivitelline layers (IPVL) prepared from laid fowl eggs, was almost negligible at 40 °C. However, motility became vigorous even at 40 °C when 2 mmol CaCl2/l was added, and the acrosome reaction was also stimulated in the presence, but not in the absence, of IPVL. The presence of deltamethrin or fenvalerate, specific inhibitors of protein phosphatase-type 2B (PP2B), did not permit the restoration of motility at 40 °C but, in the presence of IPVL, these compounds stimulated the acrosome reaction in a dose-dependent manner in the range of 1–1000 nmol/l. These results suggest that IPVL is necessary for the activation of the acrosome reaction in fowl spermatozoa and that Ca2+ plays an important role in the stimulation of motility and acrosomal exocytosis. Furthermore, it appears that the intracellular molecular mechanisms for the regulation of the acrosome reaction of fowl spermatozoa are different from those for the restoration of motility, i.e. protein dephosphorylation by PP2B in the former but not in the latter case.


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