Production of high purity proteins by elution of individual fractions from two-dimensional gels.

Results are presented on the production of purified myocardial proteins from two-dimensional (2-D) gels. Proteins were fixed in a native condition using potassium acetate and then eluted into an aqueous solution. Homogeneous tropomyosin and myosin light chain fractions and a number of nonidentified myocardial proteins present on 2-D gels were obtained.     

Pyrans,their analogs,and related compounds

Reaction of 4, 4-dichloroflavine (I) with sulfurylchloride affords 2, 3, 3, 4, 4-pentachloroflavan (II). Hydrolysis of II gives 2-hydroxy-3, 3-dichloro-4-flavanone (III), while alcoholysis with aqueous alcohols yields 2-alkoxy-3,3-dichloro-4-flavanones (IVa, b). Treatment of III with SOCl₂ gives 2,3,3-trlchloro-4-flavanone (V), which with caustic alkali or sodium ethoxide is converted into o-(1-phenyl-2, 2-dichlorovinyloxy)benzoic acid (VIc) or its ethyl ester (VIb), respectively.For Part XLII, see [7].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1167–1170, September, 1970.     

Amphiphilic graft copolymers with poly(oxyethylene) side chains: Synthesis via activated ester intermediates—properties

Amphiphilic graft copolymers were synthesized via activated ester substitution of derivatives of fumaric acid with amino-functionalized methoxypoly (oxyethylene)s (MPEO-NH₂) of different molecular weights. The monomeric activated esters, isopropyl pentachlorophenyl fumarate (PCPFA) and isopropyl succinimido fumarate (SIFA), were copolymerized with styrene (St) or N-vinyl pyrrolidone (VP) at equimolar ratio. The polymeric-activated esters proved to be good precursors for grafting of definite amounts of MPEO-NH₂. The aminolysis of the succinimide esters and VP-containing copolymers proceeded with gel formation due to extensive hydrogen bonding. The hydrodynamic behavior, the emulsifying ability, the thermal properties, and crystallinity of the graft copolymers were studied as a function of their molecular characteristics. The length of the PEO grafts and the degree of grafting are the factors which affect the melting parameters and the crystallinity of the side chains. © 1994 John Wiley & Sons, Inc.     

Core-shell nanostructures from single poly(N-vinylcaprolactam) macromolecules: stabilization and visualization

Formation of core-shell poly(N-vinylcaprolactam) (PVCL) single-molecule nanostructures due to interaction of PVCL with metal ions was studied using transmission electron microscopy, 13C NMR, and light scattering. This study demonstrates that addition of CoCl2 to PVCL in its globular conformation yields unimolecular core-shell polymer particles with the core decorated with Co(II) ions. The crucial condition for formation of well-defined unimolecular nanostructures is the presence of stable globular aggregates in aqueous solution. Moreover, the metal ions should have a sufficiently high coordination number (higher than 2) to provide a cross-linking and stabilization of the core.     

Reaction of alkali-metal hypohalites with stereoisomeric 2-methyl-1-alkyl-2-methyl-4-ethynyldecahydro-4-quinolols

Isomeric 1-alkyl-2-methyl-4- (haloethynyl) decahydro-4-quinolols were synthesized by reaction of the individual stereoisomers of 1-alkyl-2-methyl-4-ethynyl-decahydro-4-quinolols with alkali solutions of potassium hypochlorite and hypobromite. 1-Chloro-2-methyl-4-ethynyl decahydro-4-quinolols are formed by the action of an alkaline solution of potassium hypochlorite on isomeric 2-methyl-4-ethynyldecahydro-4-quinolols. Hydrogenolysis of the carbon-halogen bond accompanied by hydrogenation of the CC bond was observed under conditions of catalytic hydrogenation of 1,2-dimethy1-4-(haloethynyl) decahydro-4-quinolols. Primarily hydrogenolysis of the nitrogen-halogen bond and subsequent reduction of the acetylenic bond occur in the hydrogenation of 1-chloro-2-methyl-4-ethynyldecahydro-4-quinolols. Replacement of chlorine by hydrogen and subsequent alkylation of the resulting secondary amine and formation of the hydrochlorides of the corresponding N-methyl-substituted acetylenic alcohols occur in the reaction of the chloramines with a mixture of formaldehyde and formic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 98–103, January, 1976.     

Calorimetric study of thermodynamics of production of polybutene-1, polypentene-1, 4-methylpentene-1 and properties of reagents between 0 and 670 K

The heat capacitiesC ₀ ^p of polybutene-1, polypentene-1, poly-4-methylpentene-1 and 4-methylphentene-1 were studied calorimetrically from 6 to (500–700) K. Temperatures, enthalpies of melting of various crystalline forms and the parameters of the glass transition were determined. The thermodynamic functionsH ⁰(T)?H⁰(0), S⁰(T) andG ⁰(T)?H⁰ (0) were calculated between 0 K and (500–700) K. From the calorimetric values obtained and literature data, the thermodynamic characteristics of the following processes were estimated for the corresponding alkenes-1, andcis-andtrans-alkenes-2: the polymerization of alkenes-1, the monomer-isomerization polymerization ofcis- andtrans-alkenes-2 to polyaklenes-1 and the isomerization ofcis- andtrans-aklenes-2 to alkenes-1 in the same temperature interval at standard pressure.     

Isospecific Bulk Polymerization of Propylene with the Use of ansa-Metallocenes as a Mixture of rac and meso Isomers

The effects of various pathways of the formation of catalytic systems based on the rac-Me₂SiInd₂ZrCl₂ metallocene on the activity and properties of polypropylene prepared by the bulk polymerization of propylene were studied in detail. It was found that the conditions of formation of the catalytic system affect not only its activity and the character of kinetic curves but also the molecular weight of the synthesized polymer. Propylene polymerization was studied with the use of a number of bisindenyl derivatives of zirconium, which were mixtures of rac and meso forms that differ in the nature of substituents in the Si bridge or the indenyl ligand. The conclusion was drawn that, with the use of metallocenes as a mixture of rac and meso forms, high-molecular-weight isotactic polypropylene can be prepared with high stereoregularity at a very high rate; thereby, the stage of separation of a pure rac isomer can be excluded in the synthesis of the catalyst.     

The characterization and use of different antibodies against the hsp70 major heat shock protein family for the development of an immunoassay.

The hsp70 family of major stress proteins is composed of several different members exhibiting similar structural and functional properties. In order to obtain an antiserum with wide epitope reactivity, rabbits were immunized with a mixture of native and denatured hsp70 purified from bovine muscle by ATP-affinity chromatography. Screening for antibody specificity was performed by a "sandwich" enzyme linked immunosorbent assay (ELISA). Immunoprecipitation and immunoblotting analyses demonstrated that the polyclonal antiserum obtained by us and a monoclonal antibody raised against a different preparation of antigen recognized the same determinant on the native hsp70 molecule (inducible form). With a different specificity the polyclonal antiserum recognized only the denatured monomers of the other members of the hsp70 family. These results are discussed in relation to the immunological features of the hsp70 molecule and to the development of an immunoassay for the detection of hsp70 in cell and tissue extracts.