TABLE 5.

Abilities of the N-[¹⁴C]methyl streptamine analogs formed by N-methyltransferases from the hygromycin B and spectinomycin producers to serve as amino donors to scyllo-inosose in pseudo-half-reactions catalyzed by glutamine:aminocyclitol aminotransferase from the hygromycin B producer^a

Expt no. and reactant	Keto product (cpm/10 μl)	Fraction reacted (%)b
Expt 1 (streptamine analogs methylated by hygromycin B producer as amino donors)
N-[14C]methyl-2-deoxystreptamine + scyllo-inosose	12,060	50
N-[14C]methyl streptamine + scyllo-inosose	7,751	53
N-[14C]methyl-2-epi-streptamine + scyllo-inosose	26,350	52
Expt 2 (streptamine analogs methylated by spectinomycin producer as amino donors)
N-[14C]methyl-2-deoxystreptamine + scyllo-inosose	4,524	24
N-[14C]methylstreptamine + scyllo-inosose	11,216	28
N-[14C]methyl-2-epi-streptamine + scyllo-inosose	18,828	40

^aRadioactive reactants (2⁺ charge) were separated from labeled products (1⁺ charge) by high-voltage paper electrophoresis at pH 3.6 (15).

^bFraction of total labeled streptamine derivatives that donated an amino group to scyllo-inosose, forming scyllo-inosamine (IN, Fig. 2). This is a reversible reaction, and donors are often a mixture of N¹- and N³-methylated streptamines.