scholarly journals UV PHOTODESORPTION OF METHANOL IN PURE AND CO-RICH ICES: DESORPTION RATES OF THE INTACT MOLECULE AND OF THE PHOTOFRAGMENTS

2016 ◽  
Vol 817 (2) ◽  
pp. L12 ◽  
Author(s):  
Mathieu Bertin ◽  
Claire Romanzin ◽  
Mikhail Doronin ◽  
Laurent Philippe ◽  
Pascal Jeseck ◽  
...  
Keyword(s):  
Intact Molecule

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

scholarly journals hCGbeta core fragment is a metabolite of hCG: evidence from infusion of recombinant hCG

2000 ◽  
Vol 164 (3) ◽  
pp. 299-305 ◽  
Author(s):  
RJ Norman ◽  
MM Buchholz ◽  
AA Somogyi ◽  
F Amato
Keyword(s):  
Renal Clearance ◽  
Clearance Rate ◽  
Half Life ◽  
Urine Samples ◽  
Molar Ratio ◽  
Gel Chromatography ◽  
Core Fragment ◽  
Terminal Half Life ◽  
Intact Molecule ◽  
The Mean

The availability of recombinant human chorionic gonadotrophin (r-hCG) has allowed us to measure its metabolic and renal clearance rates and to study the origin of the beta core fragment of hCG (hCGbetacf). Serum and urine samples were collected from six subjects, after an intravenous injection of 2 mg (equivalent to 44 000 IU Urinary hCG) r-hCG, and assayed for hCG and the beta subunit (hCGbeta). Urine from four of the subjects was also subjected to gel chromatography and assayed for hCGbetacf and hCG. r-hCG, administered as an intravenous dose, was distributed, initially in a volume of 3.4+/-0.7 l (mean+/-s.d.) and then in 6.5+/-1.15 l at steady-state. The disappearance of r-hCG from serum was bi-exponential, with an initial half-life of 4.5+/-0.7 h and a terminal half-life of 29.0+/-4.6 h. The mean residence time was 28. 6+/- 3.6 h and the total systemic clearance rate of r-hCG was 226+/-18 ml/h. The renal clearance rate was 28.75+/-6.2 ml/h (mean+/-s.d). hCGbetacf was detected in all urine samples collected at 6 h intervals. Over the 138 h period of urine collection, 12.9% (range 10.1-17.3% ) of r-hCG injected was recovered as the intact molecule and 1.7% (range 0.8-2.9%) was recovered as the hCGbetacf, in 4 subjects. The molar ratio of hCGbetacf to hCG in urine increased from 3.1+/-1.7%, on day 1, to 76+/-34.3% (mean+/-s.e.m.) on day 5, after r-hCG infusion, suggesting that hCGbetacf is a metabolic product of the infused r-hCG.

Fluorescent phospholipids preferentially accumulate in sub-tegumental cells of schistosomula of Schistosoma mansoni

1992 ◽  
Vol 103 (3) ◽  
pp. 823-830 ◽  
Author(s):  
S.T. Furlong ◽  
K.S. Thibault ◽  
R.A. Rogers
Keyword(s):  
Cellular Network ◽  
Biochemical Analysis ◽  
Phosphatidyl Ethanolamine ◽  
De Novo ◽  
Cell Types ◽  
Host Immunity ◽  
Epifluorescence Microscopy ◽  
Specific Cell ◽  
Back Exchange ◽  
Intact Molecule

Schistosomes do not make sterols or fatty acids de novo and thus require host lipids for survival. The acquisition of host lipids may also be an important factor in the schistosome's defense from host immunity; however, little is known about the regulation of this process. Here we have examined binding of radiolabeled and fluorescently labeled liposomes to schistosomula, and followed incorporation of fluorescent phospholipids into the worm by both morphological and biochemical methods. Saturable binding of radiolabeled phosphatidylcholine containing liposomes was observed and epifluorescence microscopy showed binding of C6-NBD-phosphatidylcholine (C6-NBD-PC), C12-NBD-phosphatidylcholine (C12-NBD-PC) and C6-NBD-phosphatidyl-ethanolamine (C6-NBD-PE) containing liposomes on the surface of the parasite. Following back-exchange with unlabeled liposomes, NBD-PC and NBD-PE were observed to be preferentially incorporated into specific cell types within the worm. Furthermore, cells which had accumulated the fluorescent lipid formed an interconnecting cellular network immediately below the tegument, identified as cytons. By contrast, fluorescein-PE was found only on the surface of the parasite and in the gut but not in the cytons. Biochemical analysis demonstrated that > 90% of the C6-NBD-PC and C12-NBD-PC remained as the intact molecule after a one hour incubation with the parasite, but that greater than 70% of the NBD-PE was converted to other lipids. These studies demonstrate that incorporation of phospholipid analogs into schistosomula can be followed morphologically and biochemically. As there was little localization of NBD-PE or NBD-PC in the gut, these analogs must be assimilated by crossing the tegument.(ABSTRACT TRUNCATED AT 250 WORDS)

Two-Site Assays of Bone Gla Protein (Osteocalcin) Demonstrate Immunochemical Heterogeneity of the Intact Molecule

1992 ◽  
Vol 38 (11) ◽  
pp. 2318-2321 ◽  
Author(s):  
L J Deftos ◽  
R L Wolfert ◽  
C S Hill ◽  
D W Burton
Keyword(s):  
Renal Failure ◽  
Monoclonal Antibodies ◽  
Clinical Studies ◽  
Normal Subjects ◽  
Human Bone ◽  
Bone Gla Protein ◽  
Serum Concentrations ◽  
Paget Disease ◽  
Linear Sequence ◽  
Intact Molecule

Abstract We developed a panel of monoclonal antibodies to human bone gla protein (BGP; osteocalcin) peptides that span the linear sequence of the molecule, specifically BGP 1-12 (N-terminal), BGP 15-30 (midregion), and BGP 38-49 (C-terminal). These antibodies were evaluated in various combinations of two-site formats in studies of serum BGP concentrations. For clinical studies, we selected from a panel of antibodies the two most sensitive antibody pairs for the intact molecule (N-C); we also used a polyclonal RIA based on BGP-C. For the two-site format, we used two N-terminal antibodies, 029 and 052, adsorbed to polystyrene beads, and radioiodinated a C-terminal antibody, 663. The standard for each of the assays was purified human BGP. The following BGP serum concentrations (microgram/L, mean +/- SE) were measured with the various assays: by the 029-663 assay, results for normal subjects were 7 +/- 3, for patients with renal failure 25 +/- 8, and for patients with Paget disease 12 +/-4; by the 052-663 assay, the respective results were 22 +/- 4, 44 +/- 12, and 31 +/- 7; by the polyclonal assay, the results were 3 +/- 0.2, 13 +/- 2, and 5 +/- 1. The two intact (N-C) assays were significantly (P < 0.01) correlated (r = 0.94), but their serum values differed by more than twofold in terms of the same BGP standard. The polyclonal assay significantly correlated with each of the intact assays (r = 0.83, 0.77), but it, too, gave different serum values for BGP. These studies demonstrate the immunochemical heterogeneity of circulating BGP, heterogeneity that is manifest even in immunoassays specific for the same region of the molecule.

scholarly journals The Immunosuppressive Activity of Plasmic Degradation Products of Human Fibrinogen

1977 ◽  
Author(s):  
T.S. Edgington ◽  
L.K. Curtiss ◽  
E.F. Plow
Keyword(s):  
Cell Response ◽  
Degradation Products ◽  
Thymidine Uptake ◽  
Immunosuppressive Activity ◽  
Human Fibrinogen ◽  
Peptide Fraction ◽  
Intact Molecule ◽  
Stimulation Of

Plasmic cleavage of human fibrinogen leads to generation of immunosuppressive activity not expressed by the intact molecule, and which is demonstrable in vitro and in vivo. This activity is not associated with the high molecular weight derivatives X, Y, D and E, but is present in the small dialyzable peptide fraction obtained from plasmic digestion. The peptides inhibit in a non-toxic fashion, the stimulation of 3H-thymidine uptake and blastogenesis of lymphocytes by phytohemagglutinin (PHA) and allogeneic cells (MLC) under conditions of both macrophage dependence and macrophage independence. The peptides also suppress the plaque-forming cell response of mice to sheep red blood cells in vivo. Approximately 30 μg peptides/culture leads to a 50% inhibition of the PHA and MLC systems, and approximately 400 μg/mouse produces a 50% suppression of the plaque-forming cell response. Intact fibrinogen chains exhibit negligible activity, but plasmic digests of Aα chain are suppressive. Consistent with derivation from the Aa chain was the demonstration that the activity was generated from limited plasmic digest of fibrinogen which produced fragment X, and this activity was soluble at 80°C for 10 minutes. The release of the active peptide by limited plasmic degradation, and the activity of these peptides at physiologic concentrations suggests that this system may be of importance in vivo in association with local fibrinogenolysis or fibrinolysis at sites of thrombosis. This has been in part substantiated by the experimental initiation of fibrinogenolysis in vivo with streptokinase.

Low Calcium Dialysate and Hyperparathyroidism

1996 ◽  
Vol 16 (1_suppl) ◽  
pp. 499-503 ◽  
Author(s):  
Rachel Duncan ◽  
Tracey Cochrane ◽  
Carol Bhalla ◽  
Jonathan Michael ◽  
Nicholas Talbot Richards ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
High Serum ◽  
Phosphate Binders ◽  
Serum Parathyroid Hormone ◽  
Aluminum Salts ◽  
Low Calcium ◽  
Increased Risk ◽  
Intact Molecule ◽  
Alkaline Phosphate

A low calcium dialysate reduces hypercalcemia from calcium-containing phosphate binders and makes phosphate control possible without the use of aluminum salts. We asked whether this might, however, lead to hyperparathyroidism. We prospectively studied serum concentrations of parathyroid hormone levels (by an immunoreactive intact molecule assay) in 173 patients on continuous ambulatory peritoneal dialysis (CAPD) who were started on a low calcium dialysate (Ca2+ 1.25 or 1.00 mmol/L) because of hypercalcemia. Median follow-up was 13.2 months (range 1 -28). Initial serum parathyroid hormone was [median (range)]: 70 (5 -1043) ng/L pre low calcium dialysate, and this rose to 130(5 -914) ng/LatO 6 months; 130 (5 -1030) ng/Lat 6 -12 months; 170 (170 1400) ng/L at 12 -18 months; and 130 (5 -1200) ng/L at 18 24 months (p = 0.0006). Twenty-two patients required a parathyroidectomy because of a sustained rise in parathyroid hormone that was not responsive to alfacalcidol and hypercalcemia. Initial serum parathyroid hormone was significantly higher in these patients at 359 (5 1073) ng/L as compared to a level of 69.5 (6 1147) ng/L in patients who did not have a parathyroidectomy (p = 0.0009). There was a significant sustained fall in mean serum corrected calcium from 2.77 (2.37 3.51) mmol/L to 2.53 (1.39 3.20) mmol/L at three months (p = 0.0006), a nonsignificant rise in mean serum alkaline phosphate from 179 (47 -1858) mmol/L to 191 (55 -1821) mmol/L (p = 0.15), and a fall in mean serum phosphate levels from 1.87 (0.59–3.18) mmol/L to 1.68 (0.45–3.6) mmol/L (p = 0.76). Our data suggest that the benefits of a low calcium dialysate in CAPD patients are balanced by an increased risk of hyperparathyroidism, and that this risk is higher in patients with an initially high serum parathyroid hormone level.

scholarly journals Effects of Lactococcus lactis on Composition of Intestinal Microbiota: Role of Nisin

2006 ◽  
Vol 72 (1) ◽  
pp. 239-244 ◽  
Author(s):  
Nete Bernbom ◽  
Tine Rask Licht ◽  
Carl-Henrik Brogren ◽  
Birthe Jelle ◽  
Anette H. Johansen ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Intestinal Microbiota ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Fecal Microbiota ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Enzyme Linked Immunosorbent Assay ◽  
Gradient Gel Electrophoresis ◽  
Intact Molecule ◽  
Human Flora

ABSTRACT This study examined the ability of (i) pure nisin, (ii) nisin-producing Lactococcus lactis strain CHCC5826, and (iii) the non-nisin-producing L. lactis strain CHCH2862 to affect the composition of the intestinal microbiota of human flora-associated rats. The presence of both the nisin-producing and the non-nisin-producing L. lactis strains significantly increased the number of Bifidobacterium cells in fecal samples during the first 8 days but decreased the number of enterococci/streptococci in duodenum, ileum, cecum, and colon samples as detected by selective cultivation. No significant changes in the rat fecal microbiota were observed after dosage with nisin. Pearson cluster analysis of denaturing gradient gel electrophoresis profiles of the 16S rRNA genes present in the fecal microbial population revealed that the microbiota of animals dosed with either of the two L. lactis strains were different from that of control animals dosed with saline. However, profiles of the microbiota from animals dosed with nisin did not differ from the controls. The concentrations of nisin estimated by competitive enzyme-linked immunosorbent assay (ELISA) were approximately 10-fold higher in the small intestine and 200-fold higher in feces than the corresponding concentrations estimated by a biological assay. This indicates that nisin was degraded or inactivated in the gastrointestinal tract, since fragments of this bacteriocin are detected by ELISA while an intact molecule is needed to retain biological activity.

THE THERMAL REVERSIBILITY OF THE MICHAEL REACTION: II. NITROKETONES AND RELATED COMPOUNDS

1964 ◽  
Vol 42 (3) ◽  
pp. 650-654 ◽  
Author(s):  
C. F. H. Allen ◽  
G. P. Happ
Keyword(s):  
Mass Spectrometer ◽  
Michael Reaction ◽  
Secondary Products ◽  
Decomposition Products ◽  
Related Substances ◽  
Michael Adducts ◽  
Intact Molecule ◽  
Thermal Reversibility ◽  
Related Compounds ◽  
The Michael Reaction

In continuation of the study of the thermal reversibility of Michael adducts, 13 γ-nitroketones were examined in the mass spectrometer, using the inlet heated at 230°. The presence of furans was indicated, arising from the intact molecule. Such remotely related substances would never have been envisaged had not the mass spectrum been available. In contrast to the behavior of delta ketonic nitriles (Part I) only normal retrogression was found. There were many secondary products resulting from extensive decomposition of the expected nitro addend. Not all the products can be isolated by classical procedures, but their presence is predictable, and can be shown by the use of the mass spectrometer. Nine simple nitro- and bromonitro-ethylenes, sensitive to heat alone, were unexpectedly stable in the heated inlet of the mass spectrometer, but did give rise to very small amounts of decomposition products. Phenyl- and 1-naphthyl-nitromethanes, which decomposed completely, gave comparable types of products. Most of these nitro compounds have previously been thermally treated by classical methods.

scholarly journals PROPERTIES OF VARIOUS ANTI-γ-GLOBULIN FACTORS IN HUMAN SERA

1965 ◽  
Vol 121 (4) ◽  
pp. 503-519 ◽  
Author(s):  
Morten Harboe ◽  
Barbara Rau ◽  
Kimmo Aho
Keyword(s):  
Physicochemical Properties ◽  
Enzymatic Digestion ◽  
Low Ph ◽  
Red Cells ◽  
Human Antibody ◽  
Rheumatoid Factors ◽  
Pepsin Digestion ◽  
Human Sera ◽  
Intact Molecule ◽  
Antigen Antibody

The serological and physicochemical properties of the following three forms of human anti-γ-globulin factors were compared: (a) rheumatoid factors; (b) Milgrom type anti-γ-globulin factors; and (c) factors directed against an antigen in human γG-globulin that is hidden in the intact molecule and revealed by enzymatic digestion at low pH. The property common to these factors is ability to interact with human γG-globulin; they are distinguishable because they react with different antigenic groups on this molecule. In all of five sera, the Milgrom type anti-γ-globulin factors were γM-globulins. They reacted with various human γG-globulin antibodies but failed to interact with γM-globulin type antibodies in agglutination and absorption experiments. When isolated from other anti-γ-globulin factors, they agglutinated red cells coated with intact anti-Rh antibodies, but failed to react with cells cells coated with pepsin-digested anti-Rh antibody. These observations indicate that the agglutinator reacts with the crystallizable, inert fragment of γG-globulin. Anti-γ-globulin activity directed against an antigen in human γG-globulin revealed by pepsin digestion was demonstrated in γG-, γA-, and γM-globulins. This anti-γ-globulin factor could be absorbed by antigen-antibody precipitates containing human antibody, which shows that the hidden antigen in human γG-globulin is revealed not only by enzymatic digestion at low pH, but also when γG-globulin is present as antibody in an antigen-antibody precipitate. Rheumatoid factors and Milgrom type anti-γ-globulin factors were also absorbed by antigen-antibody precipitates containing human antibody. The results indicate that the three distinct forms of antiγ-globulin factors may all be produced as a result of antigenic stimulation by autologous antigen-antibody complexes.

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