PubMed HealthSearch

SEARCH · PubMed Health

Results for “molecular mobilities”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Molecular Mobility of N-Acetylgalactosamine-Modified Cyclodextrins on a Polyrotaxane for Highly Efficient Liver Targeting of Antibody Chimeras and Genome-Editing Ribonucleoproteins.

Triantennary N-acetylgalactosamine (triGalNAc), which interacts strongly with the trimeric structure of asialoglycoprotein receptors (ASGPRs), is a validated platform for liver targeting. However, the intricate design and synthesis of its linkers impose high production costs and significant technical challenges. In this study, we report an alternative strategy for targeting ASGPR using monovalent GalNAc (monoGalNAc) conjugated to the cyclic molecules of polyrotaxane, which can rotate and translocate along the axial polymer chain. The intracellular uptake efficacy of monoGalNAc-modified polyrotaxane is comparable to that of triGalNAc-modified polyrotaxane and significantly higher than that of triGalNAc- or monoGalNAc-modified immobile control polymers. These results suggest that the inherent mobility of polyrotaxanes allows monoGalNAc moieties to cluster in a trivalent-like manner, thereby enhancing multivalent interactions with multiple ASGPR oligomers. The successful application of monoGalNAc-modified polyrotaxane to lysosome-targeting antibody chimeras and genome-editing nanoparticles demonstrates that this facile technology is a highly promising alternative to conventional triGalNAc.

Rotaxanes

Biochemical and immunological characterization of deoxythymidine kinase of thymidine kinaseless HeLa cells biochemically transformed by herpes simplex virus type.

Thymidine kinase (TK) from herpes simplex virus type 1 (HSV-1) biochemically transformed HeLa cells, purified by affinity chromatography, has been characterized with respect to its electrophoretic mobility, molecular weight, activation energy, substrate specificity, and immunological specificity. TK purified from HSV-1-transformed HeLa cells has the same electrophoretic mobility as TK purified from HeLa cells lytically infected with HSV-1. The sedimentation velocity of purified TK from transformed cells was similar to that previously reported for the lytic enzyme, and its molecular weight was estimated to be 70,000. The activation energy of purified transformed-cell TK was 18.3 kcal/mol. Antiserum prepared against purified HSV-1 TK, although it showed some cross-reactivity, preferentially neutralized homologous TK. The transformed-cell TK antiserum also neutralized the deoxycytidine kinase activity of HSV-1-infected cell extracts but had no effect on deoxycytidine kinase activity of HSV-2-infected cell extract. These results further support the notion that TK acquired by HeLa cells transformed by HSV-1 is of viral and not of cellular origin.

Adenosine Triphosphate

Characterization of an adenosine triphosphatase from myeloblasts infected with the avian myeloblastosis virus.

An adenosine triphosphatase (ATPase EC 3.6.1.3) was partially purified from myeloblasts of chicken infected with the avian myeloblastosis virus and some of its molecular, catalytic and immunological properties were compared with that of the ATPase purified from the virus. Both the enzymes possessed almost same electrophoretic mobility, molecular weight, S20,w value, substrate specificity, metal-ion requirement, apparent Km value and sensitivity to inhibitors and activator. Evidence also indicated immunological identity of the two enzymes. The insensitivity of this enzyme to rutamycin or ouabain and extreme sensitivity to most of the detergents, trypsin and mercurials are the remarkable properties of this enzyme.

Adenosine Triphosphatases

[Immunochemical study of subtilisins obtained from Bacillus subtilis A-50 and some of its mutants].

Physico-chemical parameters of subtilisins from the original Bacillus subtilis A-50 strain (proteolytic activity, electrophoretic mobility, molecular weight, reactions with specific inhibitors) were similar to those mentioned in the literature for the enzymes of other strains. Immunological experiment has shown, that Bacillus subtilis A-50 subtilisins with various electrophoretic mobility do not differ in their antigenic properties. Enzymes with high electrophoretic mobility from mutant strains were similar to I--III subtilisin fractions from Bac. subtilis A-50 in the antigenic characteristics. However, the antigenic heterogeneity was observed in I, II and III enzyme fractions of some mutant strains. Subtilisins studied appear to form the isoenzyme system.

Antigen-Antibody Reactions

Purification and biochemical characterization of deoxythymidine kinase of deoxythymidine kinase-deficient mouse 3T3 cells biochemically transformed by equine herpesvirus type 1.

A line of mouse 3T3 cells lacking deoxythymidine kinase (dTK-) was stably transformed to see dTK+ phenotype after exposure to ultraviolet-irradiated equine herpesvirus type 1 (EHV-1). Deoxythymidine kinase (dTK) was purified from the biochemically transformed mouse cells by affinity chromatography on deoxythymidine-Sepharose. The purified dTK from EHV-1-transformed 3T3 cells was identical to the dTK purified from dTK- 3T3 cells lytically infected with EHV-1 with respect to its electrophoretic mobility, molecular weight, substrate specificity, phosphate donor specificity, and immunological specificity. The sedimentation velocity of the purified dTK from the transformed 3T3 cells was similar to that previously reported for the enzyme in lytically infected dTK- 3T3 cells, and its molecular weight was estimated to be 87,000. Antiserum prepared against the EHV-1 dTK induced in horse cells inactivated the dTK purified from the transformed mouse cells. The Km for deoxythymidine (5 micrometers) of purified dTK from the EHV-1-transformed cells was the same as that reported for the EHV-1-induced dTK. These results further support the notion that the dTK acquired by dTK- mouse 3T3 cells after transformation by EHV-1 is of viral and not of cellular origin.

Animals

gamma-Glutamyl transferase isoenzymes in human bile.

The gamma-glutamyl transferase isoenzymes of bile were studied using electrophoretic, gel filtration, and ultracentrifugation techniques. In view of the known association of other biliary enzymes with lipids the effects of butanol extraction were investigated. The results show the presence of four isoenzymes of gamma-glutamyl transferase in bile, differing in electrophoretic mobilities, molecular size, and density. The correlation between the properties of biliary gamma-glutamyl transferase and of alkaline phosphatase is discussed.

Bile

Abnormal immunoglobulins in severe combined immunodeficiency: analysis by immunoelectrophoresis and SDS-polyacrylamide gel electrophoresis.

The plasma immunoglobulins of patients with severe combined immunodeficiency were studied by immunoelectrophoresis and, following isolation by affinity chromatography, by SDS-polyacrylamide gel electrophoresis. Immunoglobulins in plasma from the eight patients studied were immunoelectrophoretically abnormal. Although certain of the immunoglobulins in plasma from five patients could not be identified antigenically, all possessed two mu determinant-bearing proteins with abnormally fast electrophoretic mobilities. Molecular analysis of immunoglobulins of three of these patients revealed two mu heavy chains of abnormally low molecular weight which lacked the ability to polymerize into the pentameric structure of IgM. The failure of concanavalin A to precipitate these molecules suggests that they lack the carbohydrate moiety of normal IgM. Using these techniques, we documented the acquisition of normal IgM synthesis by a patient grafted with maternal leukocytes and the partial immunologic development of a child maintained under gnotobiotic conditions. In the latter patient, between the age of 1 and 4 years, an abnormal mu component disappeared from plasma and normal IgM appeared.

Chemical Precipitation

[Histones of the fungi, Endomyces magnusii and Neurospora crassa].

Histones of Endomyces magnusii and Neurospora crassa were found to consist of four main fractions similar to calf thymus histones in their electrophoretic mobilities, molecular sizes and chromatographic behaviour on Akrilex P-60. Two of them are homologous to the most conservative histones H3 and H4. Other two fractions correspond to the histones H2A and H2B; however, they have some pecularities. A fraction of N. crassa histones corresponding to the H2B was isolated in a homogeneous state by means of gel filtration. It appeared to be very similar to calf thymus histone H2B in its amino acid composition.

Amino Acids

[Use of spin labels for studying the association of adenosine, adenosine-5'-mono-, di- and triphosphate in aqueous solutions].

Possibility of spin label studies as a method of investigation of different molecular associations is considered with adenosine, adenosine-5'-mono, di- and triphosphate as examples. The proposed method is based on dependence of the parameters of spin-labelled derivatives ESR-spectra on concentration of corresponding unlabelled compounds. Being highly sensitive the method takes the advantage of obtaining not only thermodynamic characteristics of association but dynamic parameters of molecular mobility of the associates as well. It is shown by this method that base-phosphate interaction participates in nucleotide association, together with the stacking interaction.

Adenine Nucleotides

Preferential affinity of high molecular weight high mobility group non-histone chromatin proteins for single-stranded DNA.

We have subjected proteins dissociated from chicken erythrocyte or calf thymus chromatin by 0.35 M NaCl to sequential chromatography on columns containing immobilized double-stranded DNA and single-stranded DNA. At 0.2 M NaCl, 1 mM Tris . Cl (pH 7.5), the high molecular weight, high mobility group proteins (HMG-1, HMG-2, and HMG-E), were not retained by double-stranded DNA columns, but were retained by single-stranded DNA columns. Thus, in that solvent, those proteins exhibit selective affinity for single-stranded DNA. This suggests that the functions of the high molecular weight, high mobility group proteins might involve destabilizing the DNA double helix by virtue of their preferential affinity for single-stranded DNA.

Amino Acids

Electrophoretic mobility of high-molecular-weight, double-stranded DNA on agarose gels.

A new theoretical model for the migration of high-molecular-weight, double-stranded DNA on agarose gels is presented. This leads to the prediction that under certain conditions of electrophoresis, a linear relationship will exist between the molecular weight of a DNA molecule, raised to the (-2/3) power, and its electrophoretic mobility. Agarose gel electrophoresis of the fragments of bacteriophage lambda DNA produced by several restriction endonucleases confirms this relationship, and establishes some of the limits on its linearity. For this work, a polyacrylamide slab gel apparatus was modified for use with agarose gels. This apparatus has several advantages over others commercially available for agarose gel electrophoresis, including the abilities to run a larger number of samples at one time, to use lower-concentration gels, and to maintain better temperature stability across the width of the gel. The validation of the relationship developed here between molecular weight and electrophoretic mobility should make this a useful method for determining the molecular weights of DNA fragments.

DNA

Purification and properties of prothrombin modified by asbestos filtration of human plasma.

Filtration through asbestos filter (Seitz) of human plasma modified the prothrombin molecule as previously shown. Factor II could no longer be activated by physiological activators (Ca++ + phospholipid + V and Xa) but reacted readily with staphylocoagulase. The separation and purification of the modified prothrombin allowed allowed the preparation of two fractions: A small slightly modified accessory fraction, "prothrombin-asbestos-1", lost its ability to be activated by physiological activators, and its ability to be adsorbed by barium citrate, but retained the immunological reactivity of fragment 1, as well as the mobility and molecular weight of unmodified prothrombin. A main fraction, "prothrombin-asbestos-2" appeared to be a modified prothrombin which has lost its N-terminal extremity. It was not adsorbed by barium citrate and could not be activated by physiological activators. It possessed a reduced electrophoretic mobility, as well as a reduced molecular weight (39,000), which are properties similar to those of thrombin. Both fractions 1 and 2 were devoid of thrombin activity. Asbestos was thus able to break the prothrombin molecule non enzymatically, the amputation of the N terminal extremity being responsible for the new functional and physicochemical properties of the molecule. Staphylocoagulase appeared not to need the N terminal extremity of the molecule of prothrombin to form the active thrombin-coagulase complex.

Asbestos

Quantitation of human granulocyte protease inhibitors in non-purulent bronchial lavage fluids.

The predominant inhibitors of granulocyte proteases in plasma (alpha1-antitrypsin, alpha1-antichymotrypsin, and alpha2-macroglobulin) were quantitated in unconcentrated bronchial lavage fluids obtained from non-infected individuals, together with the acid-stable low molecular weight inhibitor with activity against granulocyte elastolytic and chymotrypsin-like enzymes. This latter inhibitor accounted for about 90% of the total molar concentration of granulocyte protease inhibitors in the bronchial lavage fluids. The remaining 10% consisted mostly of alpha1-antitrypsin and alpha1-antichymotrypsin. About 85% of the bronchial inhibitor was in a free form with preserved enzyme reactivity. The remaining 15% of the immunoreactive bronchial inhibitor exhibited a molecular size indicating complexation with enzymes. The major portion of alpha1-antitrypsin and alpha1-antichymotrypsin showed electrophoretic mobilities and molecular sizes similar to the native proteins but had no enzyme reactivity.

Adult

Specific assay for pregnancy-specific-beta 1-glycoprotein (Sp1-beta). Preparation of antiserum specific for SP1-beta by absorption with a crossreacting high molecular weight serum protein.

Two pregnancy-associated proteins reacting with antibody against pregnancy-specific beta 1-glycoprotein (PS beta G or SP1) were separated by means of ammonium sulphate precipitation, size chromatography and preparative zone electrophoresis. The antibody preparation was made monospecific to the beta-mobile protein by liquid phase cross-absorption of anti-SP1 immunoglobulin preparation with the isolated alpha2-mobile high molecular weight protein. The specificity of the absorbed antibody was tested in line immunoelectrophoresis, rocket immunoelectrophoresis and crossed immunoelectrophoresis.

Absorption

Partial purification and characterization of a triglyceride lipase from pig adipose tissue.

A triglyceride lipase was extracted from defatted pig adipose tissue powder with dilute ammonia and purified about 230-fold by a combination of ammonium sulfate fractionation, heparin-Sepharose 4B, DEAE-cellulose, and Sephadex G-150 column chromatographies and isoelectrofocusing electrophoresis. The enzyme was distinguishable in physical and kinetic properties from the two previously defined lipases in adipose tissue, lipoprotein lipase, and hormone-sensitive lipase. The purified enzyme was fully active in the absence of serum lipoprotein and was not stimulated by adenosine 3':5'-monophosphate-dependent protein kinase. In marked contrast to the already defined lipases, the enzyme was strongly inhibited by serum albumin. The enzyme had a molecular weigt of about 43,000, a pI of 5.2, and pH optimum of 7.0. The enzyme hydrolyzed triolein to oleic acid and glycerol, and did not exhibit esterase activity. The apparent Km for triolein was 0.05 mM. Physiological roles of this new species of lipase remained to be explored.

Adipose Tissue

The electrophoretic mobilities of 5-dimethylaminoaphthalene-1-suphonyl-glycopeptides and their relation molecular weight.

The relationship between the electrophoretic mobility at pH2.1 of dansyl-glycopeptides of known composition and their molecular weight is shown to conform with a model equation previously derived for peptides. A dansyl-glycopeptide prepared from hen's-egg ovotransferrin is degraded sequentially with two glycosidases. The molecular weight of each glycopeptide intermediate formed is determined from its electrophoretic mobility. From successive molecular-weight changes, the number and type of sugar residues lost from the parent glycopeptide can be decided and the probable composition of each intermediate determined. The notion that the method has considerable application and would permit analysis of very small quantities of glycopeptides is discussed.

Acetylglucosaminidase

Purification of retinol-binding protein from serum and urine by affinity chromatography.

A new method for the purification of retinol-binding protein from urine and serum is described. The method is based on the reversible binding of retinol-binding protein to retinoic acid linked to Sepharose and prealbumin linked to Sepharose. The yield is comparable to conventional methods using ion exchange and gel filtration and the product is an apo retinol-binding protein of high purity. The product has the same electrophoretic mobility and molecular weight and the same ability to interact with retinoic acid and prealbumin as retinol-binding protein prepared by conventional methods.

Chromatography, Affinity