Divergent substrate specificities and regioselectivities of three lipase isoforms from Cordyceps militaris: Combinatorial advantages for entomopathogenicity and prospects as biocatalysts.

Cordyceps militaris, an entomopathogenic Cordyceps mushroom, is a crucial ethnopharmacological agricultural product with applications in traditional oriental remedies in East Asia. Since lipases are reported to serve as key enzymatic equipment for entomopathogenic fungi during the host infection, the presence of various lipases with different biochemical features in C. militaris was elucidated. Three lipases from C. militaris (CML) of 60-70 kDa were isolated according to protein hydrophobicity; isoform relationships were identified by peptide mapping using liquid chromatography-electrospray ionization-tandem mass spectrometry. The CML isoforms exhibited distinct substrate specificities, which were related to the hydrophobicity of each isoform. Furthermore, the integral stereoselectivity of each lipase towards trioleoylglycerol diverged into two classes (sn-1,3 and sn-2 regioselectivity) that are rare in canonical fungal lipases. Overall, our results demonstrate that C. militaris secretes lipase isoforms with cocktail-like enzyme functions that may contribute to the entomopathogenic life cycle of C. militaris. Each CML isoform has distinct advantages for biocatalyst applications in the food and oleochemical industries.

Use of plasma exchange in methotrexate removal in a patient with osteosarcoma and acute renal insufficiency.

Acute renal failure induced by methotrexate (MTX) can be lethal because renal excretion of the drug can be delayed. Pre-existing renal impairment, abstention, or underdosage of folinic acid and inadequate hydration facilitate toxicity. The prolonged high serum levels of MTX result in severe mucositis and pancytopenia, but strategies useful to accelerate MTX removal have not been universally accepted. We report a case of a 13-year-old girl with osteosarcoma who was treated with high-dose MTX because of thoracic tumor recurrence. No side effects were observed after 2 cycles of high-dose MTX; however, after the third cycle there was a delayed MTX elimination followed by clinical toxicity. Forty hours post-MTX infusion the serum level of MTX was 5.39 x 10(-4) mol/L. Treatment was based on symptomatic measures, such as maintenance of an abundant and alkaline diuresis and parenteral administration of folinic acid. Concomitantly, plasma exchange was employed to accelerate MTX removal and reduce its toxicity. After 24 days, she was discharged from the hospital, and her renal function recovered gradually.