Immunoproteomics of membrane proteins of Shigella flexneri 2a 2457T

AIM： To screen the immunogenic membrane proteins of Shigella Aexneri 2a 2457T. METHODS： The routine two-dimensional polyacrylamide gel electrophoresis （2-DE） and Western blotting were combined to screen immunogenic proteins of S. Aexneri 2a 2457T. Serum was gained from rabbits immunized with the same bacteria. Immunogenic spots were cut out from the polyacrylamide gel and digested by trypsin in-gel. Matrix-assisted laser desorption/ionization time of flight-mass spectrometry （MALDI-TOF-MS） was performed to determine the molecular weight of peptides. Electrospray ionization （ESI-MS/MS） was performed to determine the sequences of the interesting peptides. RESULTS： A total of 20 spots were successfully identified from Coomassie brilliant blue stained gels representing 13 protein entries, 5 known antigens and 8 novel antigens. A hypothetical protein （YaeT） was detected, which might be a candidate target of vaccine. CONCLUSION： Membrane proteins of S. flexneri 2a 2457T were successfully observed by 2-DE. Several known and novel antigens were identified by mass spectrum.

An Intelligent Neural Networks System for Adaptive Learning and Prediction of a Bioreactor Benchmark Process

The adaptive learning and prediction of a highly nonlinear and time-varying bioreactor benchmark process is studied using Neur-On-Line, a graphical tool kit for developing and deploying neural networks in the G2 real time intelligent environment,and a new modified Broyden, Fletcher, Goldfarb, and Shanno （BFGS） quasi-Newton algorithm. The modified BFGS algorithm for the adaptive learning of back propagation （BP） neural networks is developed and embedded into NeurOn-Line by introducing a new search method of learning rate to the full memory BFGS algorithm. Simulation results show that the adaptive learning and prediction neural network system can quicklv track the time-varving and nonlinear behavior of the bioreactor.

RATE MEASUREMENTS OF THERMOLYSIS OF O,O-DIETHYL-S-TRIFLUOROMETHYLTHIOLOPHOSPHATE BY ^(31)p-NMR

The thermolysis of (EtO)_2P(O)SCF_3 was measured by ^(31)P-NMR with external standard method. Kinetic parameters of the reaction, i.e., order, rate constant, pre-exponential, activation energy were obtained. For constant external-standard method, It is better to choose the value of ^(31)P peak area of standard substance slightly greater than the middle value of the area of the measured compounds.

Catalysis of Phosphate by a Modified Polyethylenimine

During the past three decades,in order to mimic the action of serineproteases manymodel enzymes have been synthesized based on micellae,imidazole and polyethyleni-mines.In this note,we describe a new protease model which can(i)noncovalently bindester substrates,(ii)accept their phosphoryl groups and(iii)dephosporylate to regeneratethe original catalytic entity.It is a true catalyst.Model 1 possesses oxime groups and long hydrocarbon chains linked to amine nitro-gen of polyethylenimine.This polymer has some attractive features:(i)Being amphiphilic,1 forms intramolecular micellae which is capable of associating with esters and othersubstrates.(ii)It has very strong binding affinity for anions and marked esters.(iii)

Catalytic Cleavage of Phosphate by Modified Polyethylenimines (Ⅱ)

A series of modified polyethylenimines (PEIs) containing oxime groups and cetyl groups were prepared. The dissociated constants of oxime group and the rate constants of its reaction with p-nitrophenyl diphenyl phosphate (PNPDPP) were determined. These polymers are good catalysts for the cleavage of PNPDPP under aqueous conditions. Rate accelerations approach 10~4-10~5-fold level with turnover behavior. Reaction mechanism is analogous to that of enzyme-catalyzed kinetics.