scholarly journals Fragmentation of a mollusc haemocyanin with plasmin and immunological identification of the fragments

1981 ◽  
Vol 197 (1) ◽  
pp. 23-29 ◽  
Author(s):  
W J Gullick ◽  
E J Head ◽  
E J Wood

Haemocyanin from the gastropod mollusc Lymnaea stagnalis (pond snail) was partially digested with plasmin under a variety of experimental conditions and the products of digestion analysed by detergent/polyacrylamide-gel electrophoresis and crossed immunoelectrophoresis. Fragments were obtained corresponding to one, two, three, four and five oxygen-binding domains, one domain having a mol.wt. of approx. 50000 and containing 2 ions of Cu. The fragments obtained after extensive digestion were non-identical immunologically, and summation of their molecular weights allowed a minimal mol.wt. of 413000 to be calculated for the original, undigested, eight-domain polypeptide chain. The use of mild-digestion conditions allowed the time course and sequence of the digestion to be monitored. An initial cleavage gave a three-domain and a five-domain fragment. The three-domain fragment was resistant to further digestion. The five-domain fragment could be digested further to give, successively a four-domain, a three-domain, and finally a two-domain fragment, single-domain units being cleaved. These data form the basis for a proposed sequence for the different domains in the original chain.

1990 ◽  
Vol 36 (1) ◽  
pp. 33-41 ◽  
Author(s):  
James E. Piechura ◽  
Viswanth P. Kurup ◽  
Laureen J. Daft

Two fractions exhibiting acid protease activity (AFPI and AFPII) were isolated by extraction of membrane vesicles of Aspergillus fumigatus with Triton X-100. These two fractions produced single bands in both polyacrylamide and sodium dodecyl sulfate polyacrylamide gel electrophoresis and showed apparent molecular weights of 73 000 and 43 000, respectively. Molecular weights determined by gel filtration in the absence and presence of Triton X-100 and sedimentation velocities in analytical ultracentrifugation indicated hydrophobic characteristics, since both fractions readily aggregated and complexed with Triton X-100; both exhibited elevated enzyme activities in the presence of Triton X-100. Carbohydrate content was 93% for AFPI and 85% for AFPII. The enzymatic fractions demonstrated different pH optima in the acid range as well as different temperature stabilities. Both protease fractions cross reacted in double immunodiffusion, while in crossed immunoelectrophoresis both demonstrated five precipitin peaks, each with similar patterns. AFPI demonstrated two additional precipitin peaks in crossed immunoelectrophoresis. As determined by crossed immunoaffinoelectrophoresis, the protease fractions demonstrated galactose and mannose residues. In biotin–avidin enzyme-linked immunosorbent assay both fractions reacted with allergic bronchopulmonary aspergillosis and aspergilloma sera. It can be concluded that the two fractions with protease activity of A. fumigatus reported here may be of significance in Aspergillus-induced diseases. Key words: Aspergillus, membrane, allergens, proteases, aspergillosis.


Blood ◽  
1990 ◽  
Vol 76 (5) ◽  
pp. 887-891 ◽  
Author(s):  
BP Schick

The relationship of protein synthesis to megakaryocyte maturation has been studied in guinea pigs in vivo. Guinea pigs were injected with a single dose of [35S]methionine. Megakaryocytes and platelets were isolated daily for 4 days, and proteins from both cells were isolated by DEAE-Sephacel chromatography and analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography. All proteins in megakaryocytes corresponding to stained bands on the SDS- PAGE gels were radiolabeled at 3 hours after injection. The greatest loss of radioactivity from the megakaryocytes occurred between 1 and 3 days after injection. Only trace labeling of platelet proteins was seen at 3 hours, representing almost entirely three bands at molecular weights 47,000, 52,000, and 66,000. At 24 hours only about 13% of the maximal labeling was present, but not all proteins were labeled. The maximal labeling was at 3 days. The pattern of labeling of platelets at 3 days was identical to that of megakaryocytes at 3 hours. The protein pattern of nonmegakaryocytic marrow cells was different from that of the platelets and megakaryocytes. Data presented here suggest that most protein synthesis in megakaryocytes is completed at least 24 hours before release of the platelets to the circulation, and suggest some specificity in the proteins that are synthesized at the terminal stages of maturation.


1983 ◽  
Vol 209 (2) ◽  
pp. 519-526 ◽  
Author(s):  
A Dawson ◽  
E J Wood

Functional fragments of the haemocyanin from the gastropod mollusc Lymnaea stagnalis (freshwater snail) were obtained by partial digestion with trypsin and plasmin. The fragments were purified by ion-exchange chromatography and characterized by detergent/polyacrylamide-gel electrophoresis and crossed immunoelectrophoresis. Three types of single-functional unit fragment were isolated from the trypsin digest, and two immunologically distinct three-functional unit fragments and a single-functional unit fragment were isolated from the plasmin digest. The O2-binding behaviour of the fragments was investigated by equilibrium and kinetic methods. Over the pH range 7.0-8.2, in the presence of 10-20 mM-CaCl2, all of the single-functional unit fragments displayed non-co-operative O2 binding and showed no evidence of a Bohr or a salt effect. A Hill coefficient of less than 1.0 was obtained with one of the two three-functional unit fragments studied, whereas both of these fragments displayed a Bohr effect. Functional heterogeneity of the fragments was indicated by the variation in the O2 affinity, the P50 (partial pressure of O2 at half saturation) ranging between 0.26 and 0.77 kPa (approx. 2-6 mmHg). Stopped-flow data reflected the O2 equilibrium behaviour. Thus there was a fall in the value of the O2 dissociation rate constant from approx. 15 to 1s-1 in parallel with the increase in O2 affinity.


Blood ◽  
1990 ◽  
Vol 76 (5) ◽  
pp. 887-891 ◽  
Author(s):  
BP Schick

Abstract The relationship of protein synthesis to megakaryocyte maturation has been studied in guinea pigs in vivo. Guinea pigs were injected with a single dose of [35S]methionine. Megakaryocytes and platelets were isolated daily for 4 days, and proteins from both cells were isolated by DEAE-Sephacel chromatography and analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography. All proteins in megakaryocytes corresponding to stained bands on the SDS- PAGE gels were radiolabeled at 3 hours after injection. The greatest loss of radioactivity from the megakaryocytes occurred between 1 and 3 days after injection. Only trace labeling of platelet proteins was seen at 3 hours, representing almost entirely three bands at molecular weights 47,000, 52,000, and 66,000. At 24 hours only about 13% of the maximal labeling was present, but not all proteins were labeled. The maximal labeling was at 3 days. The pattern of labeling of platelets at 3 days was identical to that of megakaryocytes at 3 hours. The protein pattern of nonmegakaryocytic marrow cells was different from that of the platelets and megakaryocytes. Data presented here suggest that most protein synthesis in megakaryocytes is completed at least 24 hours before release of the platelets to the circulation, and suggest some specificity in the proteins that are synthesized at the terminal stages of maturation.


1981 ◽  
Vol 45 (03) ◽  
pp. 272-275 ◽  
Author(s):  
S Mikami ◽  
Y Takahashi ◽  
M Nishino ◽  
Y Okubo ◽  
H Fukui

SummaryPatterns of VIIIR:AG in the plasma and its fractions, cryoprecipitate and cryosupernatant, from various types of von Willebrand’s disease (vWd) were observed by SDS 1.5% polyacrylamide gel electrophoresis - crossed immunoelectrophoresis (SDS PAGE - CIE). VIIIR:AG in normal cryoprecipitate showed several precipitin peaks which correspond to molecular weights ranging from 8 X 105 to 1 X 10 7 daltons and are similar to those in normal plasma. Normal cryosupernatant VIIIR: AG gave smaller molecular weights from 8 X 10 5 to 2 X 10 6 daltons.VIIIR:AG in the plasma and cryoprecipitate from 2 patients with classical vWd gave low precipitin peaks with molecular weights in normal range. VIIIR:AG from 2 patients with subgroup A variant which showed fast anodal migration on the conventional CIE, presented 3 peaks with molecular weights of 8 X 105 to 3 X 106 which are similar to those in normal cryosupernatant. VIIIR: AG from 2 patients with subgroup B variant which showed normal migration on the CIE, gave normal patterns through all fractions.


Parasitology ◽  
2005 ◽  
Vol 131 (5) ◽  
pp. 723-723

Davison, A. and Blaxter, M. L. (2005) An expressed sequence tag survey of gene expression in the pond snail Lymnaea stagnalis, an intermediate vector of Fasciola hepatica. Parasitology130, 539–552.Unfortunately, an error was introduced during the authors' editing of the manuscript. Although Lymnaea stagnalis can host Fasciola hepatica under experimental conditions (Kendall, S. B. 1949, Nature163, 880–881), the impression was inadvertently given that L. stagnalis is a common intermediate vector in nature. The truth is that only some species of the genus Lymnaea are intermediate vectors for F. hepatica, such as L. truncatula.Unfortunately, an error was introduced during the authors' editing of the manuscript. Although Lymnaea stagnalis can host Fasciola hepatica under experimental conditions (Kendall, S. B. 1949, Nature163, 880–881), the impression was inadvertently given that L. stagnalis is a common intermediate vector in nature. The truth is that only some species of the genus Lymnaea are intermediate vectors for F. hepatica, such as L. truncatula.Therefore, the title of the paper could be better as ‘An expressed sequence tag survey of gene expression in the pond snail Lymnaea stagnalis, an intermediate vector of trematodes’.In the INTRODUCTION, the following line should be modified from ‘The life-cycle of F. hepatica in Lymnaea stagnalis is typical of the digenean platyhelminths …’ to ‘The life-cycle of F. hepatica in Lymnaea is typical of the digenean platyhelminths …’Otherwise, the results and conclusions are not affected.


1980 ◽  
Vol 44 (02) ◽  
pp. 111-114 ◽  
Author(s):  
Hiroshi Takayama ◽  
Minoru Okuma ◽  
Haruto Uchino

SummaryTo develop a simple method for estimation of platelet lipoxygenase (PLO) and cyclo-oxygenase (PCO) pathways, the arachidonic acid (AA) metabolism of human platelet was investigated under various experimental conditions by the use of the thiobarbituric acid (TBA) reaction and a radioisotope technique. A TBA-reactive substance different from malondialdehyde (MDA) via PCO pathway was detected and shown to be derived from the PLO pathway. Since the optimal pH and time course of its formation were different from those of MDA formation via PCO pathway, PLO and PCO pathways were estimated by quantitating the TBA-reactive substances produced by the incubation of AA either with aspirin-treated platelets or with untreated ones, respectively, each under optimal conditions. Normal values expressed in terms of nmol MDA/108 platelets were 1.17±0.34 (M±SD, n = 31) and 0.79±0.15 (n = 31) for PLO and PCO pathways, respectively.


1982 ◽  
Vol 47 (01) ◽  
pp. 014-018 ◽  
Author(s):  
H Sumi ◽  
N Toki ◽  
S Takasugi ◽  
S Maehara ◽  
M Maruyama ◽  
...  

SummaryPapain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, and UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotrypsin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10-7 - 2.12 X 10-6 M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors to plasmin was thought to be different from that to trypsin or chymotrypsin.


1979 ◽  
Vol 42 (05) ◽  
pp. 1630-1633 ◽  
Author(s):  
A G Castle ◽  
N Crawford

SummaryBlood platelets contain microtubule proteins (tubulin and HMWs) which can be polymerised “in vitro” to form structures which resemble the microtubules seen in the intact platelet. Platelet tubulin is composed of two non-identical subunits a and p tubulin which have molecular weights around 55,000 but can be resolved in alkaline SDS-polyacrylamide gel electrophoresis. These subunits associate as dimers with sedimentation coefficients of about 5.7 S although it is not known whether the dimer protein is a homo- or hetero-dimer. The dimer tubulin binds the anti-mitotic drug colchicine and the kinetics of this binding are similar to those reported for neurotubulins. Platelet microtubules also contain two HMW proteins which appear to be essential and integral components of the fully assembled microtubule. These proteins have molecular weights greater than 200,000 daltons. Fluorescent labelled antibodies to platelet and brain tubulins stain long filamentous microtubular structures in bovine lens epithelial cells and this pattern of staining is prevented by exposing the cells to conditions known to cause depolymerisation of cell microtubules.


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