Search results for "Molecular mass"

Antihypertensive effect of a bovine lactoferrin pepsin hydrolysate: Identification of novel active peptides

2012

et al.

Isolation and characterization of haemoporin, an abundant haemolymph protein from Aplysia californica.

2003

In the present study, we show the isolation and characterization of the protein haemoporin, which constitutes the second most abundant protein fraction in the haemolymph of the marine gastropod Aplysia californica. Although Aplysia is commonly used to investigate the molecular basis of learning, not much is known about the proteins in its haemolymph, which is in contact with the neurons owing to the open circulatory system of molluscs. In the native state, haemoporin is a macromolecular complex forming a cylinder with a central solvent-filled pore. The native complex most probably is a homopentamer made up from 70 kDa subunits with a molecular mass of 360 kDa and a sedimentation coefficient…

Influence of molecular weight of DNA on the determination of anti-DNA antibodies in systemic lupus erythematosus (SLE) sera by radioimmunoassay

1975

Using a radioimmunoassay (RIA) based on the Farr technique with radioactively labeled 3-H-DNA for quantitative measurements of anti-DNA antibodies in sera of patients with systemic lupus erythematosus (SLE), the influence of molecular weight of DNA (ranging from 0.1 times 10-6 to 22.0 times 10-6 daltons) on binding and precipitation in this system has been investigated. Comparing our results with mathematical models it follows that one antibody molecule is fixed on the average to a statistical DNA segment of 2 times 10-6 to 4 times 10-6 daltons. Furthermore binding capacity of the DNA was found to be independent of the molecular weight, as demonstrated in a double label experiment using 14-…

Cold stress defense in the freshwater sponge Lubomirskia baicalensis

2007

The endemic freshwater sponge Lubomirskia baicalensis lives in Lake Baikal in winter (samples from March have been studied) under complete ice cover at near 0 degrees C, and in summer in open water at 17 degrees C (September). In March, specimens show high metabolic activity as reflected by the production of gametes. L. baicalensis lives in symbiosis with green dinoflagellates, which are related to Gymnodinium sanguineum. Here we show that these dinoflagellates produce the toxin okadaic acid (OA), which is present as a free molecule as well as in a protein-bound state. In metazoans OA inhibits both protein phosphatase-2A and protein phosphatase-1 (PP1). Only cDNA corresponding to PP1 could …

Key Disulfide Bonds in an Insect Hormone Binding Protein: cDNA Cloning of a Juvenile Hormone Binding Protein of Heliothis virescens and Ligand Bindin…

1995

The hemolymph juvenile hormone binding protein (JHBP) from the early fifth instar larvae of Heliothis virescens (Lepidoptera, Noctuidae) has been purified, and three cDNA clones for this protein have been isolated from a fat body cDNA library constructed in bacteriophage λZAP XR. The deduced amino acid sequence of the full-length clone predicts a mature protein consisting of 224 residues, a molecular mass of 24 976 Da, and a p/ of 5.29. Comparison of the amino acid sequence to that of the previously described JHBP from Manduca sexta shows 51 % overall identity with highly conserved N- and C-terminal regions. One of the three clones bound photoactivatable analogs of juvenile hormones with mu…

A method for eluting DNA in a wide range of molecular weights from agarose gels

1991

We have developed a simple and rapid method for recovering DNAs of a wide range of molecular weights from agarose gels. A DNA-containing gel slice is placed on a Parafilm sheet in the center of a circular (positive) electrode and covered with a drop of buffer, while a linear (negative) electrode is placed on the top of the gel and driven about 1 mm into the gel itself. When a continuous current is applied, the DNA migrates into the buffer toward the circular electrode. We have obtained almost total recovery of DNAs up to 10 kb in size. Our method may also be used, under appropriate conditions, for higher molecular weight DNAs. The yield and all the biological assays performed on the DNAs ob…

Analysis of protein composition of red wine in comparison with rosé and white wines by electrophoresis and high-pressure liquid chromatography-mass s…

2009

Wine proteins not only influence wine stability but are also being discussed as potential allergens. Proteins from red, rose, and white wines were enriched by dialysis and lyophilization followed by separation by SDS-PAGE. Significant differences were detected in the protein compositions of the analyzed wine varieties, and the major protein bands were identified by mass spectrometry after in-gel digestion with trypsin. In German Portugieser red wine, a total of 121 tryptic peptides were identified, which were attributed to 12 grape proteins and 6 proteins derived from yeast. Among the identified constituents are several proteins considered to influence wine stability and previously describe…

Formation of Levan from Raffinose by Levansucrase ofZymomonas mobilis

2004

Levansucrase (EC 2.4.1.10.) of Zymomonas mobilis 113S can perform the polymerisation of fructose moiety from raffinose to levan concomitantly with a release of non-catabolised melibiose into the medium. The kinetic parameters of the levansucrase-catalysed reaction provide even higher reaction velocities on raffinose as compared to sucrose, particularly at low substrate concentrations. A decreased value in the number of the average molecular mass (Mn = 1693 kDa), an increased intrinsic viscosity (η = 49.47 cm3/g), and a diminished Huggin's constant (K' = 0.67) are intrinsic to the levan synthesis from raffinose, indicating certain structural peculiarities compared to a polysaccharide obtaine…

Mobility of Acetylated Histones in Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis

1999

Abstract We describe an altered mobility for acetylated histone isoforms in sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Isoforms of histones H3 and H4 with a higher acetylation degree have a slightly faster electrophoretic mobility. Since acetylation neutralizes the positive charge of the e-amino group of lysine, without significantly changing the molecular mass of the protein, the acetylation-dependent mobility shift could be explained by the increase of the net negative charge of the SDS–histone complexes. A possible consequence of this differential mobility for the acetylation site determination by protein microsequencing from SDS gels is discussed.

1976

Poly[sulfadiazineacrylamide] (5), labeled with 14C in the main chain, was synthesized and its molecular weight viscosimetrically determined by comparison with unlabeled samples of poly[sulfadiazineacrylamide] with similar molecular weights which were determined by membrane osmometry. The material showed a polymer-specific prolongation of its systemic behaviour in mice. Rates of excretion of the polymer were negligibly low, whereas the toxicity was considerable. It was concentrated in the liver during the course of the experiment, but no affinity toward the PC6 plasmacytoma in mice could be detected. Poly[sulfadiazinacrylamid] (5) mit 14C-Hauptkettenmarkierung wurde synthetisiert und sein Mo…