Isoelectric focusing study of radiation damage to dry conalbumin.

The effect of gamma-rays on iron-free conalbumin was studied by isoelectric focusing technique. The results obtained can be interpreted on the basis of radiation-induced conformational changes of the macromolecules through a cleavage of disulphide bridges. Treatments with reagents acting on disulphide bridges lead to isoelectric focusing patterns that confirm this hypothesis.     

Isoelectric focusing of mosquito esterases in the presence of Triton X-100

Summary Triton X-100 improves nonspecific esterase solubilization from mosquito samples and also leads to increased resolution in an isoelectric focusing electrophoresis.Acknowledgments. This research was supported by a US Army contract/grant DAMD 17-77-C-7018, US Army Medical Research and Development Command, Washington, DC and by the Office of Naval Research.     

Isoelectric focusing of the serum vitamin D transport protein (DBP) and the polymorphism of Gc protein. Significance in anthropology]

The authors confirm the analogy between Gc and DBP as a result of analytic studies by isoelectrofocusing and labeling of Gc with 3H vitamin D3. The presence of a relationship between Gc polymorphism and the amount of sunshine in a given region is discussed.     

Isoelectric fractionation of desialyzed interferon

Riassunto Proteine urinarie di coniglio contenenti interferone sono state desializzate mediante neuraminidasi e sono state separate simultaneamente ai controlli mediante elettroforesi su poliacrilammide con gradiente di pH. La rimozione dell'acido sialico produce una notevole modificazione del profilo elettroforetico con diminuzione dell'attività interferonica avente punti isoelettrici inferiori a pH 6.3. Il risultato indica che almeno in parte l'interferone contiene acido sialico.

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This work was supported by a grant from the Consiglio Nazionale delle Ricerche, Roma, Gruppo Nazionale di Medicina Sperimentale.     

Mitogenic action of neuraminidase

Summary A new effect of NCV on lymphocytes is demonstrated. This property is the capacity to act as a mitogen in and of itself. The possible mechanisms of this phenomenon are discussed.     

Effet de la neuraminidase sur l'activité phagocytaire d'Amoeba proteus Effect of neuraminidase on phagocytosis activity inAmoeba proteus

Summary Phagocytosis activity ofAmoeba is greatly reduced after treatment with neuraminidase, at concentrations that do not affect normal motile behavior.     

The effect of neuraminidase on the rabbit urinary interferon

Riassunto Proteine urinarie di coniglio contenenti interferone con una attività di 5000 U/mg sono state desializzate mediante neuraminidasi. La rapida e completa rimozione dell'acido sialico non si accompagna alla scomparsa della attività antivirale e pertanto, se l'interferone contiene acido sialico, quest'ultimo non ha un ruolo nell'attività biologica.     

Effectiveness of intranasal immunization with Myxovirus influenzae neuraminidase in mice]

An intranasal immunization with a A/PR8/34-isolated NA, protected mice as well as the whole virus and A/Hong Kong/1/68 virus against a subsequent infection with mice-adaptated A/PR8/34 strain.     

Effect of intratumoral injection of bacterial and viral neuraminidase in rats]

We studied the effect of neuraminidase injection in rat's tumor at different doses: 5,10,50,100, 500 U and we concluded that: There was no difference between the rats treated with 5,10,50 U and the controls. The y died 3 weeks after the injection. But the rats treated by 100 at 500 U of NA died quickley, in the week, of long metastases.     

Alteration of cell shape in the early chick embryo mesoderm by neuraminidase

Summary Living chick embryo mesoderm cells (stages 3 to 5) were exposed to neuraminidase. The mesoderm cells changed shape losing their long thin processes and become like primitive streak cells, with short flat processes. Ruthenium red staining of such treated embryos shows that the surface coat on the mesoderm cells is reduced in thickness. These results show that cell shape in the chick embryo mesoderm is at least partly determined by the thickness and the composition of the surface coat.Acknowledgment. It is a pleasure to thank Professor F. Beck for the facilities of the Department of Anatomy, University of Leicester, and Mr. G. L. C. McTurk of the University of Leicester Scanning Electron Microscope Unit for operating the ISI 60 SEM. Mr Jeff Smith and Mrs Doris Duncan gave us valuable technical assistance and Dr. A. J. Rowe kindly allowed us to use the facilities of the Electron Microscope Unit, University of Leicester School of Biological Sciences, in specimen preparation.     

Isoelectric variants of the principal polypeptide (p 30) of different strains of murine oncornaviruses]

The major murine oncornavirus polypeptide p 30 (30,000 daltons), which bears the conventional group-specific (gs) determinants, can be separated by isoelectric focusing into four classes, with isoelectric points (pI) of 5.5, 5.9, 6.7 and 7.1. All the Moloney stocks tested have a pI 5.9 p 30, while p 30's with three to four different pI values are found to coexist in other stocks, with the pI 6.7 form predominating in Gross virus stocks.