Search results for "SECR"

Translational fusion to the Pir4 cell wall protein as a general and efficient method for cell surface immobilization or growth medium secretion of re…

2008

Deletion and insertion mutants of HBsAg particles

1992

We have found previously that hybrid 22-nm HBsAg particles can be created by insertion of short antigenic sequences into the HBV major envelope protein [1]. We have now performed a detailed deletion mutagenesis of the S gene of HBV encoding HBsAg. Deletion of the 51 C-terminal amino acids including most of the third and all of the fourth hydrophobic domain of the S protein did not affect particle assembly and secretion. However, secretion of 22-nm particles was abolished by minor deletions in the N-terminal region. Insertion and deletion/substitution mutants carrying a poliovirus epitope at the N-terminus and the preSl region at the C-terminus have been characterized.

Effect of carboxymethyl cellulose concentration on rheological behavior of milk and aqueous systems. A creep and recovery study

2009

Carboxymethyl cellulose (CMC) is an anionic polysaccharide used mainly as stabilizer and thickener agent. The purpose of this study was to investigate the effect of CMC concentration on viscoelasticity of dairy and aqueous model systems through the analysis of creep and recovery tests. The viscoelastic properties of different concentrations of CMC (0.75, 1.00, 1.25, and 1.50% w/w) in two milk systems (skimmed milk and whole milk) were compared with those of the same concentration of biopolymer in aqueous solution. Creep curves were fitted to a six parameter mechanical model (Burger + Kelvin-Voigt), whereas an empirical equation was used for recovery. The creep and recovery properties of sam…

Functional analysis of the cysteine residues and the repetitive sequence ofSaccharomyces cerevisiaePir4/Cis3: the repetitive sequence is needed for b…

2003

Identification of PIR/CIS3 gene was carried out by amino-terminal sequencing of a protein band released by β-mercaptoethanol (β-ME) from S. cerevisiae mnn9 cell walls. The protein was released also by digestion with β-1,3-glucanases (laminarinase or zymolyase) or by mild alkaline solutions. Deletion of the two carboxyterminal Cys residues (Cys214-12aa-Cys227-COOH), reduced but did not eliminate incorporation of Pir4 (protein with internal repeats) by disulphide bridges. Similarly, site-directed mutation of two other cysteine amino acids (Cys130Ser or Cys197Ser) failed to block incorporation of Pir4; the second mutation produced the appearance of Kex2-unprocessed Pir4. Therefore, it seems th…

Hunting the plant surrender signal activating apoplexy in grapevines after Neofusicoccum parvum infection

2021

SummaryApoplectic breakdown from Grapevines Trunk Diseases (GTDs) has become a serious challenge to viticulture in consequence to drought stress. We hypothesise that fungal aggressiveness is controlled by a chemical communication between host and colonising fungus.We introduce the new concept of a “plant surrender signal” accumulating in host plants under stress and triggering aggressive behaviour of the strain Neofusicoccum parvum (Bt-67) causing Botryosphaeriaceae-related dieback in grapevines.Using a cell-based experimental system (Vitis cells) and bioactivity-guided fractionation, we identify trans-ferulic acid, a monolignol precursor, as “surrender signal”. We show that this signal spe…

Secretion of Protein-bound Hydroxyproline from Moss Callus Cells

1988

Abstract A glycoprotein rich in hydroxyproline was found in wall preparations of callus cells of the moss Physcomitrium pyriforme Brid. It is apparently attached to the non-cellulosic polysaccharides of the wall, and the majority is extractable by boiling the wall fraction or by using a chaotropic salt at room temperature. A pulse-chase technique was used to study the transport of this protein to the wall. Cytochalasin B seems to inhibit its secretion from the callus cells. Some of this wall-associated protein is probably secreted from the cells into the medium. Electron microscopic evidence shows vesicular activity in the cytoplasm and secretion and incorporation into the wall layers (not …

New macrolactones from the defensive salivary secretion of soldiers of the african termite Pseudacanthotermes spiniger

1999

The salivary defensive secretion of large soldier termites of the species Pseudacanthotermes spiniger contains two novel macrocyclic lactones [22-keto-hexacosanolide (2) and 2-hydroxy-24-keto-octacosanolide (3)] together with the already known macrolactone hexacosanolide (1). In addition, the secretion contains important amounts of a polysaccharide based mainly upon β-glucopyranose, β-glucosamine and N-acetyl-β-glucosamine in equal amount.

ChemInform Abstract: New Macrolactones from the Defensive Salivary Secretion of Soldiers of the African Termite Pseudacanthotermes spiniger.

2010

The salivary defensive secretion of large soldier termites of the species Pseudacanthotermes spiniger contains two novel macrocyclic lactones [22-keto-hexacosanolide (2) and 2-hydroxy-24-keto-octacosanolide (3)] together with the already known macrolactone hexacosanolide (1). In addition, the secretion contains important amounts of a polysaccharide based mainly upon β-glucopyranose, β-glucosamine and N-acetyl-β-glucosamine in equal amount.

Determination of the stability of protein pools from the cell wall of fungi.

2002

Stability of the protein populations present in the cell wall of three ascomycetous fungi Candida albicans, Saccharomyces cerevisiae and Yarrowia lipolytica was investigated. Cell wall proteins were either labeled with biotin or radiolabeled with amino acids, and chased for a period of time representing several generations. Proteins linked by non-covalent or covalent bonds were separated and their turnover was analyzed. No significant turnover took place during the chase period, and in fact radioactive proteins were accumulated in the wall during the period possibly by transfer through the secretory pathway. This transfer did not involve de novo protein synthesis; it was inhibited by azide,…

The Receptor Functions of Endogenous C1q, a Subcomponent of the First Component of Complement, on Peritoneal Macrophages

1982

Abstract C1q, the Fc recognizing subcomponent of the first complement component was shown to be synthesized by peritoneal macrophages. Evidence is presented that C1q serves during the secretion phase as Fc binding protein on the membrane of these macrophages. A dose-dependent inhibition of Fc rosette formation occured when the macrophages were pretreated with anti-C1q -F(ab') 2 . The C3b rosette formation was not affected. In addition, preincubation of peritoneal macrophages with anti-C1q -F(ab') 2 abolished specifically the polyanion mediated stimulation to secrete dose and time dependently lysosomal enzymes. There was no polyanion-induced enzyme release after incubation of polyanions with…