scholarly journals ON THE ROLE OF VIRUS SULFHYDRYL GROUPS IN THE ATTACHMENT OF ENTEROVIRUSES TO ERYTHROCYTES

1960 ◽  
Vol 112 (3) ◽  
pp. 455-478 ◽  
Author(s):  
Lennart Philipson ◽  
Purnell W. Choppin
Keyword(s):  
Virus Particle ◽  
Human Erythrocytes ◽  
Hemagglutinating Activity ◽  
Sulfhydryl Groups ◽  
Present Communication ◽  
Sulfhydryl Reagents ◽  
Thiol Compounds ◽  
Virus Particles ◽  
Receptor Sites

Many animal viruses possess the ability to agglutinate erythrocytes. In most but not all cases hemagglutination is due to the virus particle itself, and appears to result from the mechanical bridging of two or more erythrocytes by virus particles which attach to receptor sites on each erythrocyte (1, 2). Thus, attachment of virus particles to erythrocytes is a prerequisite for hemagglutination, and prevention of absorption of virus prevents hemagglutination. Among the enteroviruses, many ECHO viruses and some strains of Coxsackie B3 virus agglutinate human erythrocytes (3-7), and the evidence indicates that hemagglutination is due to the virus particle itself (3, 5, 6). The precise mechanism of attachment of enteroviruses to cells is unknown. Chymotrypsin treatment of erythrocytes prevents the absorption of some ECHO viruses (8). This suggests that the receptor sites on the erythrocyte may be at least in part protein in nature. The present communication is concerned with the mechanism of attachment of enteroviruses to cells. It is shown that sulfhydryl reagents block the hemagglutinating activity of enteroviruses. Treated virus fails to absorb to erythrocytes. Thiol compounds restore the hemagglutinating activity of enteroviruses treated with mercaptide-forming sulfhydryl reagents. The effect of sulfhydryl reagents on the infectivity of some enteroviruses is also described.

MODIFICATION OF OZONE DAMAGE TO PHASEOLUS VULGARIS BY ANTIOXIDANTS, THIOLS AND SULFHYDRYL REAGENTS

1968 ◽  
Vol 48 (6) ◽  
pp. 569-574 ◽  
Author(s):  
H. C. Dass ◽  
G. M. Weaver
Keyword(s):  
Ascorbic Acid ◽  
Phaseolus Vulgaris ◽  
Lactic Dehydrogenase ◽  
Sulfhydryl Reagents ◽  
Thiol Compounds ◽  
Ozone Injury ◽  
Ozone Sensitivity ◽  
Cysteine Hydrochloride ◽  
White Bean

Representative cultivars of white bean (Phaseolus vulgaris) were treated with selected antioxidants, thiol compounds and sulfhydryl reagents and then exposed to ozone under laboratory conditions. Severity of the bronzing disorder was influenced by such treatments, as was the activity of peroxidase and lactic dehydrogenase enzymes.Dust applications of ascorbic acid and nickel-N-dibutyl dithiocarbamate markedly reduced ozone injury, the latter compound being the most effective. Decreased ozone sensitivity was also noted following treatment of a susceptible and a tolerant cultivar with cysteine hydrochloride and glutathione.The severity of bronzing was increased over that of the control plants by the application of sulfhydryl reagents, namely parachloromercuribenzoate and N-ethyl maleimide. Necrotic stipple of the upper surface of the lamina, a symptom associated with the bronzing disorder, was induced following treatment with the sulfhydryl reagents without exposure to ozone.Ozone fumigation increased peroxidase activity and decreased lactic dehydrogenase activity. Similar effects were observed following treatment with parachloromercuribenzoate. Neither enzyme showed response to the application of cysteine hydrochloride.The role of protein sulfhydryls is discussed in relation to ozone damage and the bronzing disorder.

Mg2+-activated ATP hydrolysis and sulfhydryl groups in membranes from human erythrocytes

1970 ◽  
Vol 48 (5) ◽  
pp. 604-612 ◽  
Author(s):  
Frances M. Smith ◽  
Jacob A. Verpoorte
Keyword(s):  
Atp Hydrolysis ◽  
Enzymatic Reaction ◽  
Maximal Activity ◽  
Maximum Activity ◽  
Human Erythrocytes ◽  
Sulfhydryl Groups ◽  
Sulfhydryl Reagents ◽  
Rate Of Reaction ◽  
Rate Profile ◽  
Sigmoid Shape

The ATP-hydrolyzing activity of membranes prepared from human erythrocytes depends on the presence of Mg2+ ions. Maximum activity is observed when the concentrations of Mg2+ and ATP are equal. The pH–rate profile of the enzymatic reaction shows a maximum at pH 7.8. The ATP-hydrolyzing activity has decreased to half the maximal activity at pH 6.3 and 9.8, respectively. The enzyme is inhibited by sulfhydryl reagents like p-chloromercuribenzoate (p-CMB) and N-ethylmaleimide. Membranes that are titrated with NaOH or treated with p-CMB lose up to 30% of their protein content. This loss is reversed when Mg2+ or Mg2+ plus ATP is added. However, neither Mg2+ nor Mg2+ plus ATP detectably alters the rate of reaction between the sulfhydryl groups and specific reagents, nor protects the ATP-hydrolyzing activity from inhibition by p-CMB. The amount of protein which dissociates from the membrane increases with pH. The curve describing this extraction has a sigmoid shape with an inflection point at pH 10.2. Maximum solubilization is obtained at pH 11.2. Thus the results indicate that sulfhydryl groups and also the structure of the membrane are important for the ATP-hydrolyzing activity.

scholarly journals Location and Role of Free Cysteinyl Residues in the Sindbis Virus E1 and E2 Glycoproteins

2007 ◽  
Vol 81 (12) ◽  
pp. 6231-6240 ◽  
Author(s):  
Christopher B. Whitehurst ◽  
Erik J. Soderblom ◽  
Michelle L. West ◽  
Raquel Hernandez ◽  
Michael B. Goshe ◽  
...  
Keyword(s):  
Virus Particle ◽  
Disulfide Bonds ◽  
Sindbis Virus ◽  
Rna Virus ◽  
Virus Maturation ◽  
Virus Particles ◽  
Native Virus ◽  
Mature Virus Particle ◽  
Liquid Chromatography Tandem Mass

ABSTRACT Sindbis virus is a single-stranded positive-sense RNA virus. It is composed of 240 copies of three structural proteins: E1, E2, and capsid. These proteins form a mature virus particle composed of two nested T=4 icosahedral shells. A complex network of disulfide bonds in the E1 and E2 glycoproteins is developed through a series of structural intermediates as virus maturation occurs (M. Mulvey and D. T. Brown, J. Virol. 68:805-812, 1994; M. Carleton et al., J. Virol. 71:1558-1566, 1997). To better understand the nature of this disulfide network, E1 and E2 cysteinyl residues were labeled with iodoacetamide in the native virus particle and analyzed by liquid chromatography-tandem mass spectrometry. This analysis identified cysteinyl residues of E1 and E2, which were found to be label accessible in the native virus particle, as well as those that were either label inaccessible or blocked by their involvement in disulfide bonds. Native virus particles alkylated with iodoacetamide demonstrated a 4-log decrease in viral infectivity. This suggests that the modification of free cysteinyl residues results in the loss of infectivity by destabilizing the virus particle or that a rearrangement of disulfide bonds, which is required for infectivity, is blocked by the modification. Although modification of these residues prevented infectivity, it did not alter the ability of virus to fuse cells after exposure to acidic pH; thus, modification of free cysteinyl residues biochemically separated the process of infection from the process of membrane fusion.

scholarly journals THE ROLE OF SULFHYDRYL GROUPS IN THE BLEACHING AND SYNTHESIS OF RHODOPSIN

1952 ◽  
Vol 35 (5) ◽  
pp. 797-821 ◽  
Author(s):  
George Wald ◽  
Paul K. Brown
Keyword(s):  
Protein Denaturation ◽  
Sulfhydryl Groups ◽  
Amino Groups ◽  
Hydrogen Atoms ◽  
Sulfhydryl Reagents ◽  
Excitation Process ◽  
Sh Groups ◽  
Sulfhydryl Compound

The condensation of retinene1 with opsin to form rhodopsin is optimal at pH about 6, a pH which favors the condensation of retinene1 with sulfhydryl rather than with amino groups. The synthesis of rhodopsin, though unaffected by the less powerful sulfhydryl reagents, monoiodoacetic acid and its amide, is inhibited completely by p-chloromercuribenzoate (PCMB). This inhibition is reversed in part by the addition of glutathione. PCMB does not attack rhodopsin itself, nor does it react with retinene1. Its action in this system is confined to the —SH groups of opsin. Under some conditions the synthesis of rhodopsin is aided by the presence of such a sulfhydryl compound as glutathione, which helps to keep the —SH groups of opsin free and reduced. By means of the amperometric silver titration of Kolthoff and Harris, it is shown that sulfhydryl groups are liberated in the bleaching of rhodopsin, two such groups for each retinene1 molecule that appears. This is true equally of rhodopsin from the retinas of cattle, frogs) and squid. The exposure of new sulfhydryl groups adds an important element to the growing evidence that relates the bleaching of rhodopsin to protein denaturation. The place of sulfhydryl groups in the structure of rhodopsin is still uncertain. They may be concerned directly in binding the chromophore to opsin; or alternatively they may furnish hydrogen atoms for some reductive change by which the chromophore is formed from retinene1. In the amperometric silver titration, the bleaching of rhodopsin yields directly an electrical variation. This phenomenon may have some fundamental connection with the role of rhodopsin in visual excitation, and may provide a model of the excitation process in general.

Improved Virus Particle Counting by Direct Sedimentation onto EM Grids

1981 ◽  
Vol 39 ◽  
pp. 404-405 ◽  
Author(s):  
Mahlon F. Miller ◽  
Edward J. Rdzok
Keyword(s):  
Virus Particle ◽  
Thin Section ◽  
Vertical Position ◽  
Present Communication ◽  
Millipore Filter ◽  
Virus Particles ◽  
Negative Stain ◽  
Particle Counting ◽  
Rotor Core ◽  
Reliable Procedure

Investigators who have attempted to sediment virus particles directly onto EM grids have reported problems with: a) tearing of plastic support films covering grid openings, b) uneven distribution of virus due to depression of support films in grid openings during ultracentrifugation, c) failure of sedimented and stained particles to adhere to support films, and d) lack of uniformity of negative stain. The design of a new particle counting rotor and its use in preparing particulate specimens for counting by either the pseudoreplication or thin section methods was previously reported. In the present communication, a simple and reliable procedure is described in which this rotor is utilized to sediment virus particles directly onto grids for counting. The rotor (Fig. 1) operates in the Beckman AirfugeTM tabletop ultracentrifuge.In preparation for counting, 500 mesh copper grids are sandwiched between parlodion support films and 5 mm2 Millipore filter squares (Fig. 2) which conveniently holds grids in a vertical position at the base of sector cells in the rotor core (Fig. 1).

scholarly journals Role of membrane sulfhydryl groups in stimulation of renin secretion by sulfhydryl reagents

1991 ◽  
Vol 39 (5) ◽  
pp. 867-873 ◽  
Author(s):  
Philip S. Doh ◽  
Cheol Joo Lee ◽  
Peter M. Hwang ◽  
Kyung Woo Cho ◽  
Thomas W. Honeyman ◽  
...  
Keyword(s):  
Sulfhydryl Groups ◽  
Renin Secretion ◽  
Sulfhydryl Reagents ◽  
Stimulation Of

Characterization of a canine adenovirus hemagglutinin

1971 ◽  
Vol 17 (2) ◽  
pp. 151-155 ◽  
Author(s):  
R. G. Marusyk ◽  
T. Yamamoto
Keyword(s):  
Animal Species ◽  
Hemagglutinating Activity ◽  
Human Group ◽  
Trypsin Treatment ◽  
Rat Erythrocytes ◽  
Virus Particles ◽  
Naturally Occurring ◽  
Receptor Sites ◽  
Wide Range

The hemagglutinating activity of the canine adenoviruses was found to be more than 80% associated with both the intact and incomplete ('empty') virus particles, the remaining complete hemagglutinating activity being associated with a naturally occurring soluble penton dimer structure. Trypsin treatment of the hemagglutinin – red blood cell complex and receptor-competition experiments, using purified fiber component to block the receptor sites on the red blood cells, indicate that there are different receptors for infectious canine laryngotracheitis (ICL) virus and infectious canine hepatitis (ICH) virus.The ICL adenovirus was found to hemagglutinate human and rat erythrocytes but not those of a number of other animal species. Using human group 'O' erythrocytes the ICL virus associated hemagglutinating activity was found to occur over a wide range in temperature and pH, and certain purification procedures, such as fluorocarbon treatment and sonic oscillation, were found to inactivate the hemagglutinin rapidly.

Spontaneous Production of Type C Virus Particles in a Culture Derived from Rat Embryo Cells

1972 ◽  
Vol 30 ◽  
pp. 288-289
Author(s):  
Elizabeth S. Priori ◽  
T. Shigematsu ◽  
B. Myers ◽  
L. Dmochowski
Keyword(s):  
Virus Particle ◽  
Mouse Embryo ◽  
Calf Serum ◽  
Embryo Cell ◽  
Virus Particles ◽  
Extracellular Virus ◽  
Mouse Embryo Cell ◽  
Mature Virus Particle ◽  
Embryo Cells ◽  
Type C

Spontaneous release of type C virus particles in long-term cultures of mouse embryo cells as well as induction of similar particles in mouse embryo cell cultures with IUDR or BUDR have been reported. The presence of type C virus particles in cultures of normal rat embryos has not been reported.NB-1, a culture derived from embryos of a New Zealand Black (NB) rat (rats obtained from Mr. Samuel M. Poiley, N.C.I., Bethesda, Md.) and grown in McCoy's 5A medium supplemented with 20% fetal calf serum was passaged weekly. Extracellular virus particles similar to murine leukemia particles appeared in the 22nd subculture. General appearance of cells in passage 23 is shown in Fig. 1. Two budding figures and one immature type C virus particle may be seen in Fig. 2. The virus particles and budding were present in all further passages examined (currently passage 39). Various stages of budding are shown in Figs. 3a,b,c,d. Appearance of a mature virus particle is shown in Fig. 4.

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