scholarly journals Haemosiderin-like properties of free-radical-modified ferritin

1986 ◽  
Vol 240 (1) ◽  
pp. 297-300 ◽  
Author(s):  
M J O'Connell ◽  
H Baum ◽  
T J Peters

Conjugated-Schiff's-base-type fluorescence was measured in iron-depleted samples and chloroform extracts of human spleen haemosiderin. Incubation of ferritin with liposomes and ascorbate led to the formation of compounds with similar fluorescence properties. Analysis of protein subunits by SDS/polyacrylamide-gel electrophoresis confirmed that ferritin was damaged in incubations with ascorbate. Since previous studies have shown that intact ferritin is resistant to proteolytic degradation, it is suggested that haemosiderin may be a product of oxidative reactions involving ferritin and lipid.

1980 ◽  
Vol 58 (6) ◽  
pp. 712-716 ◽  
Author(s):  
Shirley Dobrofsky ◽  
W. F. Grant

Self-incompatibility, a prefertilization event, and self-sterility, a postfertilization event, have both been suggested as causes for differences in seed set between cross- and self-pollinated florets in Lotus corniculatus L. Ovary protein subunits of selfed, crossed, and unpollinated florets of L. corniculatus cv. Mirabel were studied using polyacrylamide gel electrophoresis. Banding patterns differed for all three conditions. Ovary protein differences were found prior to the time fertilization is known to occur, thereby providing evidence that self-incompatibility is at least partially responsible for the reduced seed set after self-pollination.


1975 ◽  
Vol 55 (3) ◽  
pp. 667-672 ◽  
Author(s):  
K. R. PRESTON ◽  
W. WOODBURY ◽  
R. A. ORTH ◽  
W. BUSHUK

Protein subunits obtained by reduction of gliadin and glutenin from Triticum aestivum L. em. Thell. (AABBDD), Triticum monococcum L. (AA), Aegilops squarrosa L. (DD) and Secale cereale L. (RR) were examined by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. Seven of the twelve gliadin subunits and nine of the fifteen glutenin subunits present in T. aestivum had molecular weights (MW’s) similar to subunits present in both T. monococcum and A. squarrosa. An additional five gliadin and five glutenin subunits present in T. aestivum had MW’s similar to subunits present in T. monococcum or A. squarrosa. S. cereale had a lower number of gliadin and glutenin subunits. However, three of four gliadin subunits and eight of nine glutenin subunits had MW’s similar to subunits present in the Triticum–Aegilops groups. These results have been used to consider evolutionary relationships in the Triticinae.


Author(s):  
G. L. Brown

Bismuth (Bi) stains nucleoproteins (NPs) by interacting with available amino and primary phosphate groups. These two staining mechanisms are distinguishable by glutaraldehyde crosslinking (Fig. 1,2).Isolated mouse liver nuclei, extracted with salt and acid solutions, fixed in either formaldehyde (form.) or gl utaraldehyde (glut.) and stained with Bi, were viewed to determine the effect of the extractions on Bi stainina. Solubilized NPs were analyzed by SDS-polyacrylamide gel electrophoresis.Extraction with 0.14 M salt does not change the Bi staining characteristics (Fig. 3). 0.34 M salt reduces nucleolar (Nu) staining but has no effect on interchromatinic (IC) staining (Fig. 4). Proteins responsible for Nu and glut.- insensitive IC staining are removed when nuclei are extracted with 0.6 M salt (Fig. 5, 6). Low salt and acid extraction prevents Bi-Nu staining but has no effect on IC staining (Fig. 7). When nuclei are extracted with 0.6 M salt followed by low salt and acid, all Bi-staining components are removed (Fig. 8).


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.


1979 ◽  
Author(s):  
M Ribieto ◽  
J Elion ◽  
D Labie ◽  
F Josso

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.


1979 ◽  
Author(s):  
C Cierniewski ◽  
T Krajewski ◽  
E Janiak

Various studies on the interaction of immobilized mammalian fibrinogen and fibrin monomers with some fibrinogen derivatives demonstrated the presence of two sets of polymerization sites in the mammalian fibrinogen molecule. We obtained the same results while investigating the fibrinogen molecules of other classes of vertebrates /Pisces. Amphibia. Aves/. Despite significant differences among their subunit structures, all of them contain polymerization sites homologous to mammalian counterparts. Moreover, due to great functional similarity, fibrinogen or fibrin monomers of the analyzed species of Pisces. Amphibia. Aves and Mammalia interacted in a specific way with immobilized pig fibrin monomers or fibrinogen, respectively. Using these pig affinity adsorbents, fibrinogen and fibrin monomers of different vertebrates were isolated directly from plasma and analyzed by SDS polyacrylamide gel electrophoresis. Polypeptide compositions of eluted proteins were identical to those obtained for corresponding fibrinogen preparations isolated by cold-ethanol fractionation method. It appears to indicate that the nature of polymerization sites in vertebrate fibrinogens is alike.


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