Enzyme which catalyzes the acetylation of polyamines. Substrate specificity: norspermidine = spermidine >> spermine > N(1)-acetylspermine. This highly regulated enzyme allows a fine attenuation of the intracellular concentration of polyamines. Also involved in the regulation of polyamine transport out of cells. Also acts on 1,3-diaminopropane and 1,5-diaminopentane. acetyl-CoA + an alkane-alpha,omega-diamine = an N-acetylalkane-alpha,omega-diamine + CoA + H(+) acetyl-CoA + spermidine = CoA + H(+) + N(1)-acetylspermidine acetyl-CoA + spermine = CoA + H(+) + N(1)-acetylspermine Amine and polyamine degradation; putrescine degradation; N-acetylputrescine from putrescine: step 1/1. Homodimer. Belongs to the acetyltransferase family.