High affinity 3H-phenylalanine uptake by brush border membrane vesicles from whole larvae of Aedes aegypti (AaBBMVw)

摘要: Abstract Brush border membrane vesicles from whole Aedes aegypti larvae (AaBBMVw) are confirmed to be valid preparations for transport studies. The Abdul-Rauf and Ellar method was used isolate AaBBMVw that were frozen, stored several months, transported a distant site, thawed study Na + -coupled, 3 H-labeled, phenylalanine (Phe) uptake. affinity all components of the uptake very high with half maximal values in sub-micromolar range. By contrast K 0.5 Phe 0.2 mM 26 mM calculated Phe-induced electrical currents Xenopus oocytes heterologously expressing Anopheles gambiae symporter (co-transporter), AgNAT8, buffer 98 mM . What accounts >1000-fold discrepancy substrates between BBMV oocyte experiments? Is it because Ae. BBMVw whereas An. transfect oocytes? More likely, is exposed [Na ] micromolar range transporter(s) being surrounded by native lipids. contrast, measurements made at 100,000 times higher AgNAT8 foreign frog results show osmotically sealed; time-course has -induced overshoot, pH optimum ∼7 low. virtually unchanged when replaced or Li but decreased Rb This approach resolving discrepancies data on solute transporters such as over-expressed flux corresponding highly expressed vesicles, may serve model similar studies add biochemistry molecular biology efforts identify targets development new methods control disease-vector mosquitoes.