Sodium Periodate Concentration Research Articles

Protein A Immobilized Poly(Methylmethacrylate-Co-Hydroxyethylmethacrylate) Microbeads for IgG Adsorption

Poly(methylmethacrylate- co-2-hydroxyethylmethacrylate) microbeads in the size range of 1.5-2.0μm were prepared by a phase inversion polymerization. The hydroxyl groups were activated by periodate oxidation, and the active ligand, i.e., protein A was immobilized via a spacer-arm, i.e., hexamethylene diamine (HDMA) by using a cross-linker, i.e., glutaraldehyde and protein A. The optimal concentration obtained for modifications are as follows: sodium periodate concentration: 0.467 × 10−2mmol/mL; HMDA concentration: 3.5 × 10−2mmol/mL; and glutaraldehyde concentration: 0.7 × 10−6mmol/mL. Yields of immobilization of protein A onto the plain and periodate oxidized microbeads were found very close, and were in the range of 0.01-0.02 mg protein A/g microbeads. The optimal conditions for immobilization are as follows: the initial protein A concentration: 0.1 mg/mL; temperature: 25°C; pH: 9.5; and immobilization time:120 min. Incorporation of protein A at these conditions resulted in 0.825 mg protein A/g microbeads. The HIgG adsorption onto these protein A incorporated microbeads was 41 mg HIgG/g microbeads.

A potential cell affinity sorbent: Fibronectin carrying poly(EGDMA/HEMA) microbeads

Both non-swellable and swellable poly(EGDMA/HEMA) microbeads were produced by suspension copolymerization. These microbeads were modified by immobilization of a spacer-arm (hexamethylene diamine, HMDA) and fibronectin. The optimal values for modifications were as follows: the sodium periodate concentration 1.0 mg ml-1; the HMDA concentration 4 mg ml-1; and the glutaraldehyde concentration 0.070 μg ml-1. Adsorption of fibronectin onto the plain and periodate-oxidized poly(EGDMA/HEMA) microbeads were very similar, and were 0.025-0.035 mg fibronectin per g polymer, respectively. Fibronectin immobilization on poly(EGDMA/HEMA) microbeads were studied at different temperature, time and pH using single protein solution containing different amount of proteins. The optimal values for immobilizations were as follows: the initial fibronectin concentration 0.1 mg ml; temperature + 25°C; pH 7; the immobilization time 120 min. Both fibroblastic 3T3 and epithelial MDBK cells were attached to these unmodified and modified microbeads. The attachments of both 3T3 and MDBK cells, especially to the fibronectin-immobilized swellable microbeads, were very high. Almost 96% of the 3T3 cells available in the cell culture medium did attach to these microbeads (2345 ± 98 cells per mg of polymer).

An evaluation of the role of carbohydrate epitopes in immunity to Trichinella spiralis.

A study is described in which the role of carbohydrate epitopes in the generation of protective immunity to Trichinella spiralis was investigated. Antigen preparations were treated with increasing molar concentrations of sodium periodate, which is known to degrade carbohydrate moieties by cleaving one side of the hexose ring, and a suitable protocol was established for the selective degradation of carbohydrates with the retention of protein integrity. Using excretory/secretory (ES) proteins, both sodium periodate treated and in their native form, vaccination experiments have shown that sodium periodate treated antigens are as effective as native ES proteins in the generation of both active and passive immunity. This indicates that peptide epitopes alone can induce protective immunity to T. spiralis.

Evidence for the functional role of monosialoganglioside GM1 in synaptic transmission in the rat hippocampus

The hippocampal slices were incubated with compounds which hydrolyze, modify or bind with sialic acid containing molecules. The efficiency of synaptic transmission was tested in the presence of these compounds. The size of the evoked extracellularly recorded potential following Schaffer collateral stimulation was used as an indicator of synaptic transmission efficiency. Sodium periodate (10 mM) and sodium perchlorate (59.2 mM) evoked a reversible (after washout) decrease in the size of the population spike. Higher concentration of sodium periodate (60 mM) abolished the size of the population spike, which was only poorly reversible after washout. Tetanus toxin, which binds to polysialogangliosides, and neuraminidase from Vibrio cholerae (an enzyme which splits off sialic acid from polysialogangliosides, leaving GM1 intact, and splits off sialic acid from sialoglycoproteins) had no influence on the size of the population spike. Cholera toxin, which binds to GM1, slightly reduced the size of the population spike. Incubation of the slices with neuraminidase from Arthrobacter ureafaciens (an enzyme which splits off sialic acid from all gangliosides, including GM1, and from sialoglycoproteins) abolished the population spike after 5 h. GM1 antiserum abolished the potential after approximately 100 min. The conclusion is drawn that of all gangliosides only GM1 is necessary to support synaptic transmission in Schaffer collateral-pyramidal cell synapses.

Migration Inhibition Produced by Sodium Periodate Oxidation of the Macrophage Membrane, and Reversal by Sodium Borohydride

Guinea pig peritoneal exudate cells were harvested 3 to 4 days after the intraperitoneal injection of Marcol oil. The washed cells were exposed to various concentrations of sodium periodate in phosphate-buffered saline (PBS) at pH 7.4 for 10 min at +4 degrees C. The cells were then used in the in vitro migration assay, and migration was consistently inhibited at concentrations from 10(-3) to 10(-5) M. The viability of the macrophages was not affected by this treatment. Sodium borohydride (10(-3) to 10(-5) M) in PBS for 10 min at pH 7.4 reversed the periodate effect. Experiments with purified macrophages showed that sodium periodate has a direct effect on macrophage function rather than an indirect effect via the potentiation of migration inhibition factor. In support of this, the in vitro spreading of macrophages on glass substrate for 1 h has been shown to be inhibited. This spreading inhibition can also be reversed by treatment with sodium borohydride. These results provide a new approach to understanding the biological significance and role of macrophage migration inhibition.

Graft copolymerization to cellulose by sodium periodate

AbstractIt has been shown that acrylic monomer is easily grafted to cellulose by sodium periodate. The apparent activation energy of graft copolymerization is found to be 10.5 Kcal./mole, which indicates that polymer radicals formed by the attack of sodium periodate on cellulose initiate the graft copolymerization. The rate of the reaction increases with increasing reagent concentration of the reagent up to a certain concentration. At higher concentrations, sodium periodate produces more aldehyde groups in the graft copolymer and the grafted chains become shorter. The apparent number of graft‐initiating points is almost constant and independent of the sodium periodate concentration. Studies of homogeneous polymerization indicate that sodium periodate seems not to terminate the reaction of growing polymer radicals. On the other hand, when dialdehyde cellulose prepared previously by sodium periodate oxidation is grafted with methyl methacrylate, the grafted chain is shorter in the range of high content of aldehyde. The above observation indicates that the aldehyde groups formed in cellulose during the grafting reaction are likely to terminate the growing graft chains. The chain transfer constants for several sugars and alcohols with acrylonitrile as monomer were measured. The constants for sugars were found to be always higher than those for alcohols. The x‐ray diffraction patterns of the grafted cellulose with acrylonitrile give, in addition to the typical patterns of crystalline cellulose, lattice distances of 5.2 and about 3 A. which are attributed to the grafted polyacrylonitrile. The intensity distribution curve along the Debye‐Scherrer ring at the lattice distance of 5.2 A. leads to the conclusion that the crystallites of grafted polyacrylonitrile might be oriented along the direction of the fiber axis of the preexisting stock polymer. Studies on samples of cellulose of different fine structure would support the inference that, in the range of relatively low per cent grating the growing grafted chains on the surface of cellulose crystallites are oriented with the formation of crystallites along the lamellar plane of cellulose crystallites.

Cross fertilization with the sperm of Arbacia lixula

1. 1. Experiments on cross fertilization were carried out with the eggs of Paracentrotus liuidus and the sperm of Arbacia lixula. The per cent cross fertilization was greatly increased when the fertilization medium contained a mixture of Arbacia egg water and glycine. Egg water alone or glycine alone had much less effect. Crystalline serum albumin had an effect similar to that of glycine, α-alanine was also effective, but β-alanine had no effect at the concentrations used. 2. 2. A combination of certain low concentrations of sodium periodate and Arbacia egg water also increased the per cent cross fertilization. Higher concentrations of sodium periodate inactivated the egg water. 3. 3. Pretreatment of the gametes with either glycine or NaIO 4, followed by fertilization in the presence of egg water, did not result in as high percentages of cross fertilization as in the case of fertilization in the presence of glycine and egg water or sodium periodate and egg water. 4. 4. Very little cross fertilization occurred in the presence of egg water alone at a pH of about 8 or below. At a more alkaline pH (8.7), a relatively high percentage of cross fertilization occurred. A combination of egg water plus glycine or egg water plus sodium periodate increased the per cent cross fertilization at pH values below 8, indicating that this effect is independent of alkaline pH. A combination of egg water and ATP did not increase the per cent cross fertilization at pH values below 8.

The action of certain polysaccharides on fertilization in the sea urchin egg

1. 1. Several polysaccharides were tested for their action on fertilization in the eggs of Arbacia punctulata and Echinarachnius parma. 2. 2. One sample of heparin (from Hynson, Westcott, and Dunning Co.); a mucopolysaccharide, the human H substance, extracted from pig mucin; and “fucoidin,” a polysaccharide preparation from Fucus vesiculosis, inhibited elevation of the fertilization membrane in relatively low concentrations. Heparin from the Upjohn Co. and also from the Vitrum Co. were relatively inactive. Heating the solutions of Upjohn and Vitrum heparin increased their activity. Oxidation of these polysaccharides with appropriate concentrations of sodium periodate removed their inhibiting activity. 3. 3. Using Hynson, Westcott, and Dunning heparin and Arbacia punctulata eggs the following information was obtained: a) 0.2 per cent heparin prevents cleavage if the eggs are fertilized in the heparin solution. b) If the eggs are fertilized in sea water and then placed in 0.2 percent heparin three to five minutes after fertilization, cleavage occurs. This is true also if the fertilization membrane and hyaline layer are removed to allow penetration of the heparin to the fertilized egg surface. c) Heparin inhibits membrane elevation in eggs from which the jelly coats have been removed. d) Heparin inhibits the membrane elevation which normally occurs when Arbacia punctulata eggs are activated with hypertonic sea water. These results are interpreted as an indication that heparin can prevent cleavage by inhibiting normal fertilization. Also, the heparin has, at least in part, an action on the protoplasmic surface of the egg. 4. 4. Possible chemical mechanisms which might explain the inhibiting activity of heparin are discussed.