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PubMed1979

Heterogeneity of hemoglobin gamma chains in normal newborns and in cases of alpha and beta thalassemia.

The ratio of Ggamma to Agamma was studied in 13 normal healthy newborns and in eight neonates with hydrops fetalis due to homozygous alpha-thalassemia. The findings in the normal healthy newborns agreed with those of earlier reports. In homozygous alpha-thalassemia the Ggamma and Agamma ratio appeared generally lower than in healthy control newborns, but one of the hydrops fetalis cases had a very high Ggamma value. In all 13 normal healthy newborns, in 8 patients with homozygous alpha-thalassemia, and in 4 patients with homozygous beta-thalassemia, Tgamma chains with threonine at position 75 were detected in addition Igamma chains with isoleucine at position 75. In homozygous alpha-thalassemia, the Tgamma-to-Igamma ratio seemed lower and in homozygous beta-thalassemia higher than in normal newborns.

Alanine↗

PubMedDate not supplied

Isoforms of heavy and light chains of cardiac myosins from rat and rabbit.

The light chains of myosin from atrial and ventricular tissues from rat and rabbit were examined by one- and two-dimensional polyacrylamide gel electrophoresis. The myosin heavy chains were electrophoretically isolated, digested after denaturation in sodium dodecyl sulfate with papain and proteinase from S. aureus V8, and the resulting peptides resolved in one-dimensional gel electrophoresis. The peptide patterns of myosin heavy chains from atrial and ventricular tissues of adult rabbits were different, indicating differences in their primary structures. No such differences could be detected in a total of around 180 peptides produced by the two proteinases from the myosin heavy chains of adult rat atrial and ventricular tissues. With regard to light chains, the same migration pattern was observed for atrial and ventricular tissues from both rat and rabbit. The atrial light chains ALC1 and ALC2 migrated with molecular weights lying between those of the ventricular light chains VLC1 and VLC2. In two-dimensional electrophoresis, the corresponding light chains from rat and rabbit co-migrated. An additional light chain was observed in foetal ventricles, which exhibited identical electrophoretic properties to ALC1 from adult atrial tissues. In rat myofibrillar preparations from atrium and ventricle, an unidentified protein (x) occurred in the region of light chain-1 but with a more acidic isoelectric point, which seems to be related to the developmental stage of these tissues and which could not be detected in rabbit heart tissues or in any skeletal muscles.

Animals↗

PubMedDate not supplied

The idiopathic dilated cardiomyopathy in man. A biochemical and molecular study on myosin.

We studied subunit composition and Ca(++)-activated ATPase activity of myosin isolated from atria and ventricles of hearts explanted from patients suffering from idiopathic dilated cardiomyopathy. At variance with previously published data, we have been unable to detect in the ventricular subendocardial layers a significant amount of myosin atrial-like light chain 1 (ALC1), which has been reported to be related to some hemodynamic features of the hypertrophied and failing heart. Such a subunit was not visible in the septum and in the subepicardial layers either. On the contrary, in both atria a ventricular-like light chain 2 (VLC2) was found. The nature of this additional light chain was confirmed on the basis of two-dimensional electrophoresis and immunoblotting techniques with polyclonal antibodies reacting with VLC2. In these patients we also observed a depressed Ca(++)-activated ATPase activity, both in atrial and ventricular myosin. The explanation for this finding in ventricles still remains obscure since neither myosin light chains, nor myosin heavy chains showed any difference between patients with dilated cardiomyopathy and controls. On the contrary, in atria we clearly identified changes consistent with the expression of myosin heavy chains of ventricular type and VLC2, which can account for the depressed Ca(++)-activated ATPase activity.

Calcium-Transporting ATPases↗

PubMed1987

Phosphorylation in vitro of human fibrinogen with casein kinase TS and characterization of phosphorylated sites.

Human fibrinogen was phosphorylated by casein kinase TS. The [32P]phosphate incorporated varied between 0.5 and 1 mol of phosphate per mole of fibrinogen. The phosphate was localized to Ser523 and Ser590 and serine and threonine residues between amino acids 259 and 268 in the A alpha-chain. In addition, Thr416 and Ser420 were phosphorylated in the gamma'-chain, which is a variant of the gamma-chain, constituting 7-10% of the gamma-chain population. The functional significance of casein kinase TS-induced phosphorylation of fibrinogen remains unknown; however, a slight but consistent increase of the turbidity in a gelation assay was observed for phosphorylated compared to unphosphorylated fibrinogen.

Casein Kinases↗

PubMed1994

Physicochemical characterization of PEG-PPG conjugated human urokinase.

Human urokinase (UK) was conjugated with polyethylene glycol-polypropylene glycol (PEG-PPG) and its physicochemical properties were examined. PEG-PPG modification decreased the activity for plasminogen activation, but increased the half-life of this protein when injected intravenously in rabbits. Kinetic analysis of PEG-PPG conjugated UK (PEG-PPG-UK) revealed that the kcat for plasminogen activation decreased 1/5-fold with the increase of Km in comparison with that of UK, although these parameters for cleavage of synthetic substrate (S-2444) did not change. However, the inhibitor constant of PEG-PPG-UK for plasminogen activator inhibitor 1 (PAI 1) was equal to that of UK. Peptide mapping analysis revealed that PEG-PPG binding sites were mainly determined to be Lys 35, 46, 61, 98, 120 and 135 in A-chain and Lys 211, 300, 318, 338, 348, 383 and 404 in B-chain. In addition, the modification rates of A and B-chain were 37.8% and 19.8% on average, respectively.

Animals↗

PubMed1983

A novel neutral oligosaccharide chain found in polysialoglycoproteins isolated from Pacific salmon eggs. Structural studies by secondary ion mass spectrometry, proton nuclear magnetic resonance spectroscopy, and chemical methods.

A novel carbohydrate chain possessing a hitherto unknown disaccharide unit, alpha-L-Fuc leads to D-GalNAc, has been isolated from salmon egg polysialoglycoproteins on alkali-borohydride treatment. Salmon egg polysialoglycoproteins contain O-glycosidically linked neutral pentasaccharide chains in addition to a number of oligosialosyl group containing sugar chains. Composition analysis of the neutral pentasaccharide gave fucose, galactose, 2-acetamido-2-deoxygalactose, and 2-acetamido-2-deoxygalactitol in a molar ratio of 1:2:1:1. The structure was determined to be alpha-L-Fuc(1 leads to 3)-beta-D-GalNAc-(1 leads to 3)-beta-D-Gal(1 leads to 4)-beta-D-Gal(1 leads to 3)-D-GalNAcol by the following three major procedures: First, the sequential order of the constitutional monosaccharides was determined by secondary ion mass spectrometry before and after permethylation. Second, linkages were established by methylation analysis and Smith degradation and hydrazinolysis-nitrous deamination studies. Third, anomeric configuration of the glycosidic linkages involved was deduced from 270-MHz proton nuclear magnetic resonance spectroscopy.

Animals↗

PubMed1999

Cell wall teichoic acids of Actinomadura viridis VKM Ac-1315T.

The cell walls of Actinomadura viridis contain poly(glycosylglycerol phosphate) chains of complex structure. On the basis of NMR spectroscopy of the polymer and glycosides thereof the following structural units were found: beta-D-Galp3Me-(1-->4)[beta-D-Glcp-(1-->6)]-beta-D-Galp-(1-->1)-++ +snGro (G1); beta-D-Galp-(1-->4)-beta-D-Galp-(1-->1)-snGro (G2); beta-D-Galp3Me-(1-->4)-beta-D-Galp-(1-->1)-snGro (G2a); beta-D-Galp-(1-->1)-snGro (G3); beta-D-Galp-(1-->1)[beta-D-Galp-(1-->2)]-snGro (G4); beta-D-Glcp-(1-->2)-snGro (G5). Glycosides G1, G2 and G3 were the predominant components of the teichoic acid: they formed the polymer chain via phosphodiester bonds involving C-3 of the glycerol residue and C-3 of the galactosyl residue which in turn glycosylates C-1 of the glycerol residue. Whether the different glycosides make up the one chain or whether there are several poly(glycosylglycerol phosphate) chains in the cell wall remains to be determined. It was suggested that the minor component G5 is located at the nonterminal end of the chains. Compound G4 which contains disubstituted glycerol residues (unusual for the teichoic acid) was also found as a minor component; this may be the glycoside of a new type of teichoic acid, or a glycoside on the terminal end of the above mentioned chains. In addition, small amounts of 1,3-poly(glycerol phosphate) chains were found in the cell wall.

Actinomycetales↗

PubMed1973

Mouse lambda-chain sequences.

Amino-acid sequences of the variable regions of three lambda chains produced by plasmacytomas of BALB/c mice are compared. Two are almost certainly identical and one differs from these by three amino acids. These findings extend our earlier conclusion on the relative uniformity of sequences in this type of immunoglobulin light chain. With amino-acid sequence data on two additional lambda chains, eight mouse lambda chains studied to date are indistinguishable and four probably differ from these by one, two, or three amino acids.

Amino Acid Sequence↗

PubMed1998

The molecular chaperone Ssb from Saccharomyces cerevisiae is a component of the ribosome-nascent chain complex.

The 70 kDa heat shock proteins (Hsp70s) are a ubiquitous class of molecular chaperones. The Ssbs of Saccharomyces cerevisiae are an abundant type of Hsp70 found associated with translating ribosomes. To understand better the function of Ssb in association with ribosomes, the Ssb-ribosome interaction was characterized. Incorporation of the aminoacyl-tRNA analog puromycin by translating ribosomes caused the release of Ssb concomitant with the release of nascent chains. In addition, Ssb could be cross-linked to nascent chains containing a modified lysine residue with a photoactivatable cross-linker. Together, these results suggest an interaction of Ssb with the nascent chain. The interaction of Ssb with the ribosome-nascent chain complex was stable, as demonstrated by resistance to treatment with high salt; however, Ssb interaction with the ribosome in the absence of nascent chain was salt sensitive. We propose that Ssb is a core component of the translating ribosome which interacts with both the nascent polypeptide chain and the ribosome. These interactions allow Ssb to function as a chaperone on the ribosome, preventing the misfolding of newly synthesized proteins.

Adenosine Triphosphate↗

PubMed1994

Dynamic changes in mRNA expression of neutrophils during the course of acute inflammation in rabbits.

To examine RNA/protein synthesis of neutrophils and related dynamic changes during the inflammatory process, we investigated mRNA expressions in neutrophils, by RNA blot hybridization analyses using 12 different rabbit gene probes. We first selected five candidate genes encoding inflammation-related proteins, i.e. tumor necrosis factor (TNF-alpha) IL-1 alpha, IL-1 beta, neutrophil activating peptide-1/IL-8 (NAP-1/IL-8) and monocyte chemoattractant protein (MCP)-1. We further selected several genes on basis of the results from gene subtraction between cDNA libraries from neutrophils at an early (5 h) and at a late (24 h) stage of casein-induced acute peritonitis in rabbits, i.e. immune activation gene-2 (Act-2), migration inhibitory factor-related protein-8 (MRP-8), MRP-14, gamma-actin, and formyl-methionyl-leucyl-phenylalanine receptor (fMLP-R), and ferritin light (L) chain. In addition to these genes we used ferritin heavy (H) chain gene, another component of the ferritin molecule. We examined mRNA expressions by cytoplasmic slot blot analysis of the above 12 genes in neutrophils obtained from blood and from various stages of casein-induced inflammation in rabbits. The observed patterns of mRNA expression kinetics were classified into three. Pattern 1: mRNAs of MRP-8, MRP-14, and gamma-actin were constitutively expressed in blood neutrophils, and increased rapidly after emigration into inflammatory sites. Pattern 2: mRNAs of IL-1 beta, NAP-1/IL-8, Act-2, and fMLP-R were undetectable in blood neutrophils, and were induced rapidly after the onset of inflammation. Pattern 3 mRNAs of ferritin L and H chain were induced slowly, and increased with progression of the inflammatory process.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2006

Unusual gamma heavy chain disease protein in a patient with splenic marginal-zone lymphoma.

We conducted an electrophoretic analysis of monoclonal gamma-globulin found in the serum of a patient with splenic marginal-zone lymphoma. This monoclonal protein showed electrophoretic mobility to the gamma region and reacted with anti-immunoglobulin (IgG) antiserum but not with anti-kappa or anti-lambda light chain antisera. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting of the monoclonal protein-rich gamma-globulin fraction extracted from the sliced gel revealed the presence of two types of abnormal IgG molecule, low- and high-molecular-weight IgG, neither of which reacted with anti-kappa or anti-lambda light chain antisera. Additionally, an abnormal high-molecular-weight gamma heavy chain was identified by reducing SDS-PAGE. These findings suggest that this monoclonal protein is composed only of gamma heavy chains of normal and larger size. The presence of abnormal serum immunoglobulin composed of only gamma heavy chain has been known as a fundamental feature of gamma heavy chain disease (HCD). However, the unique composition of monoclonal gamma-globulin makes our case distinct from typical gammaHCD, which is characterized by an abnormal truncated low-molecular-weight gamma heavy chain. Thus, the unusual monoclonal protein may have been produced by a somatic mutation of IgH gene associated with splenic marginal-zone lymphoma.

Female↗

PubMed1991

Phosphorylation of integrin in differentiating ts-Rous sarcoma virus-infected myogenic cells.

The differentiation of primary myogenic cultures requires the attachment of the cells to an extracellular matrix substrate using an integrin family receptor. These integrin receptors can be phosphorylated on both their alpha and beta chains, and it has been postulated that phosphorylation regulates the receptor function. Quail myogenic clones transformed with ts-LA24A differentiated into mature myotubes following a temperature shift to nonpermissive temperature which inactivates the viral src kinas. Phosphorylation of integrin beta-1 chain and of at least one alpha chain was detected on both serine and tyrosine. An additional alpha chain(s) with a mobility similar to alpha 5 was not phosphorylated at either temperature. Following the induction of differentiation by a temperature shift, there was a marked decrease in integrin phosphorylation of both alpha and beta integrin chains. This decrease was more prominent for serine than for tyrosine, suggesting that src could not be the only kinase involved. The drop in integrin phosphorylation correlated with the initiation of differentiation, suggesting that integrin phosphorylation could be at least part of the mechanism by which myogenic differentiation is blocked by v-src.

Animals↗

PubMed1990

The binding site of human C4b-binding protein on complement C4 is localized in the alpha'-chain.

C4b-binding protein (C4BP) is a multimeric plasma protein, which regulates the classical pathway of the C system. C4BP functions as a cofactor to factor I in the degradation of C4b and accelerates the decay rate of the C4b2a complex. We now demonstrate that C4b contains a binding site for C4BP, which is localized on the alpha'-chain of C4b. SDS-PAGE of C C4 and C4b both under reducing and nonreducing conditions was followed by a radiolabeled C4BP ligand blotting procedure. It was demonstrated that the C4BP binding site on C4b is localized on the alpha'-chain. In addition, we found C4BP binding to the alpha-chain of C4, which suggests that the binding site for C4BP becomes available after reduction of the C4 molecule. Direct binding of C4BP to the alpha- and alpha'-chains of C4 and C4b was demonstrated in a radio-labeled C4BP binding assay with the reduced and alkylated isolated chains. mAb against the alpha'-chain of C4b were prepared, characterized, and evaluated for their ability to block the binding of 125I-C4BP to C4b. Two mAb specific for the alpha'-chain of C4b were found that completely abolished C4BP binding to intact C4b. Other mAb recognizing both the alpha- and alpha'-chain of C4 and C4b demonstrated only minor inhibitory effect on the binding of C4BP to C4b. In conclusion, we have localized the C4BP binding site on the alpha'-chain of C4b and have demonstrated that this binding can be inhibited by mAb specific for the alpha'-chain.

Antibodies, Monoclonal↗

PubMed1987

T3-p28 is a protein associated with the delta and epsilon chains of the T cell receptor-T3 antigen complex during biosynthesis.

The human T cell receptor-T3 antigen complex is composed of at least five polypeptide chains. In addition to the 45-kDa/50-kDa heterodimer (alpha and beta chains) of the T cell receptor, the complex includes 25-kDa (T3-gamma) and 20-kDa (T3-delta) glycoproteins and a nonglycosylated 20-kDa (T3-epsilon) protein. Here we report that in pulse-chase biosynthetic labeling experiments we detect a new polypeptide chain (T3-p28) which is associated with the T3-delta and T3-epsilon chains during biosynthesis but not on the cell surface. T3-p28, which is not recognized by anti-T3 antibodies, can be chemically distinguished from the previously described T3-gamma chain. The carboxylic ionophore monensin blocks the apparent dissociation of T3-p28 from the T3-delta and T3-epsilon chains. Peripheral blood lymphocytes as well as all T cell leukemic lines tested contain T3-p28, except one HPB-ALL subline. Since the T3-p28 protein is only observed early in biosynthesis of T3-delta and T3-epsilon, it may function in intracellular transport or assembly of the T cell receptor-T3 complex.

Antigens, Surface↗

PubMed1996

Effects of the addition of hyaluronate segments with different chain lengths on the viscoelasticity of hyaluronic acid solutions.

The effects of the addition of sodium hyaluronate segments (sHA) with different chain lengths on the viscoelasticity of high molecular weight sodium hyaluronate (HA) aqueous solutions were studied. The additive effects of sHA depended on the chain length of sHA. Shorter sHA decreased storage (G') and loss (G") moduli, whereas longer sHA increased both moduli. In physiological saline, the effects of the addition of sHA depended on the chain length of sHA, as in aqueous solutions, except that shorter segments did not decrease both moduli. The effects of the addition of monosaccharides, i.e., N-acetyl glucosamine (GlcNAc) and sodium glucuronate (GlcANa), were also studied. Although GlcNAc increased G' and G", GlcANa decreased both moduli. A shift factor "A," which depended on chain-length effects, a sugar effect, and a salt effect, was developed to explain these additive effects quantitatively.

Carbohydrate Sequence↗

PubMed1982

Sialic acid dependent polypeptide chain heterogeneity of human fibrinogen demonstrated by two-dimensional electrophoresis.

Human fibrinogen was compared with asialofibrinogen by two-dimensional electrophoresis to evaluate the contribution of sialic acid to the heterogeneity of the gamma- and B beta-polypeptide chains. Reduced fibrinogen showed three major variants for both the gamma- and B beta-chains. In addition two minor gamma-bands with a more acidic isoelectric point than the normal gamma-chains were observed. Electrophoresis in the second dimension (SDS) suggests that these most acidic bands are gamma-chain-variants with a higher molecular weight. In asialofibrinogen only two predominant variants with more alkaline isoelectric points were present in each chain type. It is concluded that enzymatic removal of sialic acid partially reduced the heterogeneity of the gamma- and B beta-polypeptide chains of human fibrinogen, but additional sources producing charge heterogeneity must be sought.

Chemical Phenomena↗

PubMed1985

The effect of myosin phosphorylation on the contractile properties of skinned rabbit skeletal muscle fibers.

We have studied the effect of myosin P-light chain phosphorylation on the isometric tension generated by skinned fibers from rabbit psoas muscle at 0.6 and 10 microM Ca2+. At the lower Ca2+ concentration, which produced 10-20% of the maximal isometric tension obtained at 10 microM Ca2+, addition of purified myosin light chain resulted in a 50% increase in isometric tension which correlated with an increase in P-light chain phosphorylation from 0.10 to 0.80 mol of phosphate/mol of P-light chain. Addition of a phosphoprotein phosphatase reversed the isometric tension response and dephosphorylated P-light chain. At the higher Ca2+ concentration, P-light chain phosphorylation was found to have little effect on isometric tension. Fibers prepared and stored at -20 degrees C in a buffer containing MgATP, KF, and potassium phosphate incorporated 0.80 mol of phosphate/mol of P-light chain. Addition of phosphoprotein phosphatase to these fibers incubated at 0.6 microM Ca2+ caused a reduction in isometric tension and dephosphorylation of the P-light chain. There was no difference before and after phosphorylation of P-light chain in the normalized force-velocity relationship for fibers at the lower Ca2+ concentration, and the extrapolated maximum shortening velocity was 2.2 fiber lengths/s. Our results suggest that in vertebrate skeletal muscle, P-light chain phosphorylation increases the force level at submaximal Ca2+ concentrations, probably by affecting the interaction between the myosin cross-bridge and the thin filament.

Animals↗

PubMed1971

Laser Raman investigation of the effect of cholesterol on conformational changes in dipalmitoyl lecithin multilayers.

Large and abrupt changes are observed at 38 degrees C in the 1100 cm(-1) region of the Raman spectrum of aqueous dipalmitoyl lecithin multilayers. They correspond to conformational changes due to the melting of the paraffin side chains. The addition of cholesterol to the multilayers broadens but does not abolish these changes. It is suggested that the addition of cholesterol decreases the interactions between adjacent paraffin side chains of lecithin, causing a change from a cooperative to a noncooperative gel-liquid crystal transition. Removal of water from dipalmitoyl lecithin also results in a noncooperative transition strikingly similar to that caused by addition of cholesterol. Raman spectroscopy thus provides a new and sensitive probe for analyzing the structures of membranes and their constituents.

Chemical Phenomena↗