Search results for "complement"
showing 10 items of 2113 documents
A pea nuclear protein that is induced by dehydration belongs to the vicilin superfamily
2000
The purification to homogeneity of p16, a protein with an electrophoretic mobility compatible with an apparent molecular mass of 16 kDa, from nuclei of ungerminated pea embryonic axes is described. A cDNA clone of its gene, which was designated psp54, was also isolated. The psp54 cDNA contains an open reading frame coding for a 54.4-kDa polypeptide (p54). p16 corresponds to the C-terminal third of p54, although the mechanisms by which the primary polypeptide could be processed are not yet known. The sequence of p54 is 60% identical with that of the precursor of a sucrose-binding soybean protein, and, to a lesser extent (31-34%), it shares homology with some storage proteins. p16 is also 30%…
Stable Expression of Heterologous Sulfotransferase in V79 Cells: Activation of Primary and Secondary Benzylic Alcohols
1994
Abstract A sulfotransferase (ST) capable of activating 1-hydroxymethylpyrene (HMP) and 9-hydroxymethylanthracene (HMA) to mutagens was purified from rat liver. This enzyme appeared to be identical with hydroxysteroid STa, whose cDNA was cloned and stably expressed in Chinese hamster V79 cells. Several primary and secondary benzylic alcohols derived from polycyclic aromatic hydrocarbons induced gene mutations, sister chromatid exchanges (SCE) and/or cytotoxicity in these cells.
Formation and function of a complement-activating enzyme generated from factors of guinea pig serum and cobra venom
1971
An enzymatic complex can be formed by factors from guinea pig serum and cobra venom, which is able to activate C3 bypassing C1, C4 and C2. Formation and action of the enzyme are described. The action on C3 results in an activation of the terminal complement components and in membrane destruction provided suitable membrane receptors are available.
The Anaphylatoxic Peptide C3a of Guinea Pig Complement
1978
Abstract Highly purified guinea pig C3a was obtained after specific cleavage of isolated C3 by the alternative pathway enzyme VF-B in a one step procedure. It turned out to be a low molecular weight peptide with basic character (M.W. 9500; isoelectric point above 9.4). C3a represents an antigenetic determinant of its own in the native C3 molecule, different from the B determinant. Guinea pig C3a is resistant to 100°C for 10 minutes. Its smooth muscle contracting activity can be destroyed by trypsin and carboxypeptidase B. These findings indicate that guinea pig C3a is quite similar to human C3a.
LC-NMR applied to the characterisation of cardiac glycosides from three micropropagatedIsoplexisspecies
2002
Species of the genus Isoplexis are of particular interest with respect to the biochemical pathway leading to the cardenolides. It is important to determine whether or not 5β-configured compounds, typically produced by Digitalis species and used in medicine, are present together with their respective α-isomers in Isoplexis spp. Structure elucidation by LC-NMR of the products isolated from in vitro regenerated Isoplexis canariensis, I. chalcantha and I. isabelliana was carried out, and similarities were observed among the products of the three species, including the presence of digitoxigenin-type cardenolides in I. canariensis and xysmalogenin and canarigenin derivatives in I. chalcantha neve…
The gene encoding polyneuridine aldehyde esterase of monoterpenoid indole alkaloid biosynthesis in plants is an ortholog of theα/β hydrolase super fa…
2000
The biosynthesis of the anti-arrhythmic alkaloid ajmaline is catalysed by more than 10 specific enzymes. In this multistep process polyneuridine aldehyde esterase (PNAE) catalyses a central reaction by transforming polyneuridine aldehyde into epi-vellosimine, which is the immediate precursor for the synthesis of the ajmalane skeleton. PNAE was purified from cell suspension cultures of Rauvolfia serpentina. The N-terminal sequence and endoproteinase LysC fragments of the purified protein were used for primer design and for the amplification of specific PCR products leading to the isolation of PNAE-encoding cDNA from a R. serpentina library. The PNAE cDNA was fused with a C-terminal His-tag, …
Identification of Type I and IX Collagens in the Ascidian Ciona intestinalis
2001
Immunohistochemical methods showed that a type I collagen is a component of the tunic of Ciona intestinalis, involved in the encapsulation process. Since the fibril-forming collagen types are characterized by triple helical domain with a highly preserved Gly-Xaa-Yaa repeated sequence, a probe coding the fibril-forming type I collagen of the echinoderm Paracentrotus lividus was used to identify ascidian cDNA clones. Northern blot hybridization established that P. lividus probe cross-hybridizes with a 6 Kb C. intestinalis mRNA isolated from the pharynx. Using the echinodermal type I collagen cDNA as a probe several positive clones were identified. Analysis of sequence and the deduced amino ac…
C1q
2000
Publisher Summary This chapter provides information to the physical properties, structure, and function of C1q protein. This protein is made up of three individual polypeptide chains, A, B and C, which are synthesized as pre-molecules with 22, 25, and 28 amino acid leader sequences, respectively. C1q has a characteristic appearance under the electron microscope, with six globular heads connected by six collagen-like stalks forming a central fibril stem. Glucosylgalactosyl disaccharide units are linked to certain hydroxylysine residues in the collagen regions of all three chains. C1q has a critical function in host defense and clearance of immune complexes. Antibody-independent activation of…
Expression of silicatein and collagen genes in the marine sponge Suberites domuncula is controlled by silicate and myotrophin
2000
The major skeletal elements in the (Porifera) sponges, are spicules formed from inorganic material. The spicules in the Demospongiae class are composed of hydrated, amorphous silica. Recently an enzyme, silicatein, which polymerizes alkoxide substrates to silica was described from the sponge Tethya aurantia. In the present study the cDNA encoding silicatein was isolated from the sponge Suberites domuncula. The deduced polypeptide comprises 331 amino acids and has a calculated size of Mr 36 306. This cDNA was used as a probe to study the potential role of silicate on the expression of the silicatein gene. For these studies, primmorphs, a special form of aggregates composed of proliferating c…