SRM Human

Spermidine synthase (Spds) is an enzyme that plays a crucial role in the biosynthesis of polyamines, which are essential for various cellular processes such as cell growth, differentiation, and proliferation. The enzyme catalyzes the transfer of an aminopropyl group from decarboxylated S-adenosylmethionine (dcSAM) to putrescine, resulting in the formation of spermidine .

Spermidine synthase is a member of the aminopropyl transferase family and is highly specific for its substrates. The enzyme typically exists as a dimer in solution and does not require any cofactors for its activity . The human recombinant form of spermidine synthase has been extensively studied to understand its structure and function.

The enzyme’s active site contains conserved aspartate residues that are crucial for substrate binding and catalysis. These residues help in the proper positioning of the substrates, ensuring efficient transfer of the aminopropyl group . The reaction mechanism of spermidine synthase is believed to follow an S_N2 mechanism, although there is some debate about whether it occurs via a ping-pong or ternary-complex mechanism .

Human recombinant spermidine synthase is typically expressed in bacterial systems such as Escherichia coli. The recombinant enzyme is purified and characterized to study its biochemical properties and structural features. The molecular mass of the purified enzyme is approximately 33 kDa, and it shows optimal activity at physiological pH and temperature .

Polyamines, including spermidine, are involved in numerous cellular processes. They play a role in stabilizing DNA, regulating ion channels, and modulating enzyme activities. Spermidine, in particular, has been shown to have anti-aging properties and is involved in autophagy, a cellular process that degrades and recycles damaged cellular components .

The study of human recombinant spermidine synthase has significant implications for biomedical research. Understanding the enzyme’s structure and function can aid in the development of therapeutic strategies for diseases associated with polyamine metabolism. Additionally, spermidine synthase inhibitors are being explored as potential treatments for cancer and parasitic infections .