[A study of blood albumin of various animal species by the spectral luminescent method].

The functional differences of blood serum albumin of some animal species have been studied using the spectral luminescent method by comparing the binding constants K and the concentration of binding sites N of rhodamine B and rhodanmine S to albumin. It was shown that K and N depend on both the concentration of blood serum albumin and animal species and the dye used.

[Characteristics of the het mutations in the Escherichia coli chromosome causing an increase in Tn1 transposition frequency]. / Kharakteristika mutatsii het v khromosome Escherichia coli, obuslovlivaiushchikh uvelichenie chastoty transpozitsii Tn1.

Four mutations were studied which lead to increasing the frequency of transposon Tn1 translocation into different replicons. These mutations (het1, het2, het3 and het4) increase the frequency of Tn1 translocation 10-20-fold. The het1 mutation is recessive and has been localized in the 90-94.5 min region of the bacterial chromosome. The mutation effects Tn1 transposition in the presence of F plasmid only. As we have demonstrated recently, F-plasmid inhibits Tn1 transposition in Escherichia coli cells. The het1 mutation eliminates this inhibition. Unlike het2, het3 and het4 mutations, het1 is responsible for resistance to male phages f1, f2, MS2 and inhibition of conjugative transfer in F+ bacteria.

[Isolation of mutants with an increased frequency of transposon Tn1 translocations in Escherichia coli K-12 cells]. / Vydelenie mutantov s povyshennoi chastotoi translokatsii transpozona Tn1 v kletkakh Escherichia coli K-12.

Two het mutations (high efficiency of transposition) were isolated and characterized preliminarily. The mutations lead to increasing the frequency of ampicillin transposon Tn1 translocation into different replicons in Escherichia coli cells. Both mutations increase the frequency of transposition by the same degree. One of het mutations has been localized within Tn1 transposition element. This mutation seems to be similar to mutations isolated earlier (Gill et al., 1978) in the transposon Tn3 repressor gene which occurred at a high frequency and led to an increase in transposition. The other het mutation is situated in the bacterial chromosome.