Search results for "WALL"
showing 10 items of 970 documents
Genomic response programs of Saccharomyces cerevisiae following protoplasting and regeneration.
2007
Abstract Global transcription profiling during regeneration of Saccharomyces cerevisiae protoplasts was explored. DNA microarrays measured the expression of 6388 genes and wall removal resulted initially in over-expression of 861 genes that decayed later on, a behaviour expected from a transient stress response. Kinetics of expression divided the genes into 25 clusters. Transcription of the genes from clusters 14–25 was initially up-regulated, suggesting that the grouped genes permitted cell adaptation to the removal of the wall. Clustering of genes involved in “wall structure and biosynthesis” showed that most of them had initially low levels of expression that increased along the process.…
Properties of Halococcus salifodinae, an Isolate from Permian Rock Salt Deposits, Compared with Halococci from Surface Waters
2013
Halococcus salifodinae BIpT DSM 8989T, an extremely halophilic archaeal isolate from an Austrian salt deposit (Bad Ischl), whose origin was dated to the Permian period, was described in 1994. Subsequently, several strains of the species have been isolated, some from similar but geographically separated salt deposits. Hcc. salifodinae may be regarded as one of the most ancient culturable species which existed already about 250 million years ago. Since its habitat probably did not change during this long period, its properties were presumably not subjected to the needs of mutational adaptation. Hcc. salifodinae and other isolates from ancient deposits would be suitable candidates for testing …
The formation of large quartz veins by rapid ascent of fluids in mobile hydrofractures
2001
Abstract This paper aims to resolve two main problems related to the formation of quartz veins: (1) the predominance of quartz veins at shallow crustal levels and not deeper in the crust, close to the source of metamorphic fluids where the temperature sensitivity of quartz solubility is much higher than at lower, upper-crustal temperatures and (2) the formation of very large 100–1000 m scale quartz veins that would require huge amounts of fluid flow in current models of vein formation. It is proposed here that these problems are resolved by the recognition of very fast (m/s) mobile hydrofracture ascent of batches of fluid. Mobile hydrofractures are fluid-filled fractures that propagate at t…
Quality of life in elderly patients after inguinal hernioplasty
2009
Background and aim Inguinal hernia is the most frequent abdominal wall her- nias in elderly population. Surgical treatment must be aware of the cardiovascular and respiratory disease these patients are often affected by. Inguinal hernia is responsi- ble to impair the quality of life (QoL). Aim of this study was to evaluate the QoL through the Short-Form (SF)-36 questionnaire in a cohort of elderly patients undergoing inguinal hernioplasty. Materials and methods Fifteen male patients of age ≥75 years affected by sympto- matic unilateral uncomplicated inguinal hernia were included in this study. All patients undergoing inguinal hernioplasty in local anaesthesia according to the Liech- tenstei…
Molecular organization of selected prokaryotic S-layer proteins.
2005
Regular crystalline surface layers (S-layers) are widespread among prokaryotes and probably represent the earliest cell wall structures. S-layer genes have been found in approximately 400 different species of the prokaryotic domains bacteria and archaea. S-layers usually consist of a single (glyco-)protein species with molecular masses ranging from about 40 to 200 kDa that form lattices of oblique, tetragonal, or hexagonal architecture. The primary sequen ces of hyperthermophilic archaeal species exhibit some characteristic signatures. Further adaptations to their specific environments occur by various post-translational modifications, such as linkage of glycans, lipids, phosphate, and sulf…
Active Site Mapping of Xylan-Deconstructing Enzymes with Arabinoxylan Oligosaccharides Produced by Automated Glycan Assembly
2017
Xylan-degrading enzymes are crucial for the deconstruction of hemicellulosic biomass, making the hydrolysis products available for various industrial applications such as the production of biofuel. To determine the substrate specificities of these enzymes, we prepared a collection of complex xylan oligosaccharides by automated glycan assembly. Seven differentially protected building blocks provided the basis for the modular assembly of 2-substituted, 3-substituted, and 2-/3-substituted arabino- and glucuronoxylan oligosaccharides. Elongation of the xylan backbone relied on iterative additions of C4-fluorenylmethoxylcarbonyl (Fmoc) protected xylose building blocks to a linker-functionalized …
Amylopectin: a major component of the residual body inCryptosporidium parvumoocysts
2004
Amylopectin is used for carbohydrate storage in different life-stages of a number of apicomplexan parasites. We have performed an ultrastructural analysis of amylopectin granules from the oocyst residual body and sporozoites ofCryptosporidium parvum. Amylopectin granules were studiedin situand after isolation from ‘French’ press disrupted parasites, by conventional transmission electron microscopy (TEM) of sectioned oocysts and various negative staining and cryoelectron microscopy techniques. Within the membrane-enclosed oocyst residuum large amylopectin granules (0·1–0·3 μm) can be found besides a characteristic large lipid body and a crystalline protein inclusion. Smaller granules were de…
Evidence for the formation of covalent bonds between macromolecules in the domain of the wall of Candida albicans mycelial cells
1989
An O-glycosylated mannoprotein, after its incorporation into the wall, showed an increase in its molecular weight, due at least to its association with N-glycosidic sugar chain(s). This was shown by rendering the material soluble after partial degradation of the wall structure. At present it is unknown whether this phenomenon is due to an additional transglycosylation process or whether the partial degradation of the wall solubilizes a supramolecular structure formed between the original O-glycosylated protein which becomes linked either directly or indirectly through a protein to the N-sugar chain(s).
Identification of Two Mannoproteins Released from Cell Walls of a Saccharomyces cerevisiae mnn1 mnn9 Double Mutant by Reducing Agents
1999
The cell wall of Saccharomyces cerevisiae represents some 30% of the total weight of the cell and is made up of β-glucans, mannose-containing glycoproteins (mannoproteins), and small amounts of chitin (9, 15). The mannoproteins can be divided into three groups according to the linkages that bind them to the structure of the cell wall: (i) noncovalently bound, (ii) covalently bound to the structural glucan, and (iii) disulfide bound to other proteins that are themselves covalently bound to the structural glucan of the cell wall (8). Our work has focused on the disulfide-bound mannoproteins, probably the least well known of the three groups mentioned above. Previous work (25) showed that trea…
Killer toxin of Hanseniaspora uvarum
1990
The yeast Hanseniaspora uvarum liberates a killer toxin lethal to sensitive strains of the species Saccharomyces cerevisiae. Secretion of this killer toxin was inhibited by tunicamycin, an inhibitor of N-glycosylation, although the mature killer protein did not show any detectable carbohydrate structures. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular killer toxin was precipitated with ethanol and purified by ion exchange chromatography. SDS-PAGE of the electrophoretically homogenous killer protein indicated an apparent molecular mass of 18,000. Additional investigations of the primary toxin binding sites within the cell wall of sensitiv…