Cysteine Solution Research Articles

Carbonic Anhydrase in the Marine Alga Ulva pertusa

AbstractThe preparation of stable samples containing carbonic anhydrase from Ulva pertusa was achieved by using artificial sea water and 10 mM cysteine solution adjusted to pH 8.2 instead of 10 mM cysteine solution alone. When the sample was stored at 0°C in darkness the enzyme activity was retained for about 24 h. In contrast to the results obtained with land plants in previous works a remarkable inhibitory effect of low concentrations of sulfanilamide and Diamox (2‐acetylamino‐1,3,4‐thiadiazole‐5‐sulfonamide) on the activity of the enzyme was observed.

P-chloro-mercuribenzoate (PCMB) によるインフルエンザAウイルス (PR8 strain) の不活化

(1) By treating influenza A virus suspended in 0.1M phosphate buffer (pH 7) with 5×10-4M p-chloromercuribenzoate (PCMB) for 24 hours at 37°C, the infectivity which was measured by the membrane piece technique could be destroyed without affecting hemagglutinating capacity.(2) When an equal volume of an aqueous solution (pH 7) of the reactivating agent, cysteine or sodium thioglycolate, within the initial 30 minutes of the inactivation period, was added to the PCMB-treated virus, the reactivation was obtained. When cysteine or sodium thioglycolate solution was added after 60 minutes of the inactivation period, essentially no reactivation was obtained.From these results, it seemed that SH group of virus protein was necessary to manifest the infectivity, and it was concluded that the infectivity and the hemagglutinating capacity were the independent attributes respectively.

The measurement of tissue -SH

A method for the estimation of -SH content of tissue slices or small organs has been described. This involves treatment of the tissue with a known excess of a standard solution of p-chloromercuribenzoic acid, and after time has been allowed for the reaction, the excess C.M.B. is titrated potentiometrically against a cysteine solution. From the difference between this and a control titration the tissue -SH content is calculated. This method gave -SH contents of 23.4 ± 2.05 ν and 9.9 + 2.0 ν per 100 mg wet weight for slices of mouse liver and kidney.

Prolongation of the lag phase of irradiated Escherichia coli.

1. A prolongation of the lag phase in irradiated E. coli is described. The modifying effects of temperature during growth, storage of irradiated organisms, and the addition of mouse blood, inactivated rabbit serum, 0.5% cysteine solution, the nitrate of actively growing E. coli cultures, fresh spleen, liver and kidney mash, or growing non-irradiated E. coli cultures, have been studied. 2. Evidence that sublethal effects of X irradiation in bacteria differ from lethal effects is discussed.

On the effect of heavy metals on the frog ventricle

Silver and cadmium ions cause an immediate inhibition of the contractions of the frog ventricle which cannot be reversed by repeated washings with Ringer's fluid. However, a cysteine solution removes the block at once. After this occurs, contractions are usually higher than before. Cysteine only partially reverses the inhibition by copper ions and is ineffective against mercury ions.