Evaluation of lignocellulosic biomass from coconut palm as substrate for cultivation of Pleurotus sajor-caju (Fr.) Singer

The lignocellulosic biomass from coconut palm (Cocos nucifera Linn.) such as bunch waste (spathe+spadices), leafstalk (petiole), leaflets and coir pith (by-product from coir processing industry) were evaluated as substrates for cultivation of oyster mushroom, Pleurotus sajor-caju (Fr.) Singer. A low-cost mushroom shed built exclusively of coconut materials such as coconut wood and plaited coconut leaves inside a coconut plantation was used for spawn run and cropping. Leafstalk and bunch waste were superior to leaflets and coir pith in producing significantly more edible biomass of mushrooms. Biological efficiency of 58.9% was obtained in leafstalk, followed by bunch waste (56.9%), coir pith (39.7%) and leaflets (38.2%). The yield of sporophore was positively related to cellulose content and the cellulose : lignin ratio of the substrates.     

A monomeric, biologically active, full-length human apolipoprotein E

Apolipoprotein E (apoE) is an exchangeable apolipoprotein that plays an important role in lipid/lipoprotein metabolism and cardiovascular diseases. Recent evidence indicates that apoE is also critical in several other important biological processes, including Alzheimer's disease, cognitive function, immunoregulation, cell signaling, and infectious diseases. Although the X-ray crystal structure of the apoE N-terminal domain was solved in 1991, the structural study of full-length apoE is hindered by apoE's oligomerization property. Using protein-engineering techniques, we generated a monomeric, biologically active, full-length apoE. Cross-linking experiments indicate that this mutant is nearly 95-100% monomeric even at 20 mg/mL. CD spectroscopy and guanidine hydrochloride denaturation demonstrate that the structure and stability of the monomeric mutant are identical to wild-type apoE. Monomeric and wild-type apoE display similar lipid-binding activities in dimyristoylphosphatidylcholine clearance assays and formation of reconstituted high-density lipoproteins. Furthermore, the monomeric and wild-type apoE proteins display an identical LDL receptor binding activity. Availability of this monomeric, biologically active, full-length apoE allows us to collect high quality NMR data for structural determination. Our initial NMR data of lipid-free apoE demonstrates that the N-terminal domain in the full-length apoE adopts a nearly identical structure as the isolated N-terminal domain, whereas the C-terminal domain appears to become more structured than the isolated C-terminal domain fragment, suggesting a weak domain-domain interaction. This interaction is confirmed by NMR examination of a segmental labeled apoE, in which the N-terminal domain is deuterated and the C-terminal domain is double-labeled. NMR titration experiments further suggest that the hinge region (residues 192-215) that connects apoE's N- and C-terminal domains may play an important role in mediating this domain-domain interaction.