Enzymatic properties and anticancer activity of L-lysine α-oxidase from Trichoderma cf. aureoviride Rifai BKMF-4268D.

L-Lysine α-oxidase (LO) from a novel Trichoderma strain: Trichoderma cf. aureoviride Rifai shows favorable biochemical and kinetic properties (Km for L-lysine of 17.9 µmol/l, optimum pH 8.0, high stability) and significant antiproliferative activity both in vitro and in vivo. The molecular weight of LO was determined to be 115-116 kDa; the active dimer consists of two identical 57-58 kDa subunits. LO shows considerable cytotoxicity against the following tumor cell lines: K562, LS174T, HT29, SCOV3, PC3, and MCF7, with the inhibition concentration (IC50) ranging from 3.0×10 to 7.8×10 U/ml (3.2×10 to 8.2×10 mg/ml). Two human colon cancer xenografts HCT116 and LS174T and breast adenocarcinoma T47D implanted subcutaneously into Balb/c nude mice showed high sensitivity to LO with a T/C of 12, 37, and 36%, respectively (P<0.05). The antitumor efficacy of LO was observed in the absence of pronounced morbidity or toxicity in vivo. Taken together, these data suggest that LO may be considered as an effective anticancer agent for the treatment of solid tumors in vivo. This study presents promising data on the possible application of LO in clinical oncology for patients with colorectal cancer.

Alzheimer's amyloid-beta (A beta) is an essential synaptic protein, not neurotoxic junk.

Despite a decade long universal publication in favor of the view on amyloid-beta (A beta) as Alzheimer's disease culprit (solely neurotoxic for neurons and brain tissue), current scientific evidence leaves little doubt that A beta serves an essential role at synapse and in synaptic structure-functional plasticity that underlie learning and memory. Therefore, the change of A beta biology in Alzheimer's disease (as well as in a number of other human pathologies, including cardiovascular disease, neuromuscular junction disorders, NPC and Down's syndrome) may represent a physiological mechanism to compensate for impaired brain structure or function. In our own recent study A beta 1-40 rescued long term potentiation (LTP, a major model for activity-dependent CNS plasticity), while cholesterol synthesis inhibition abolished the restorative action of the A beta peptide. This study confirms that A beta protein is a functional player in synaptic structure-functional plasticity and in cholesterol neurochemical pathways. The article also calls for a need to critically re-evaluate a universal belief that transgenic mice with a transgene for amyloid-beta protein precursor (A beta PP) are a true model for Alzheimer's type neurodegeneration.