T _m data (°C) of the DNA and RNA hybrids of pyrrolidinyl PNA with α/β-dipeptide backbones.

Systema	apDNA	pDNA	mmDNA	apRNA	pRNA	mmRNA	Ref.
aegPNAb	43	32	33–36	47	31	29–37	53
acpcPNA	53	<20	24–29	42	<20	<20–24	125 and 132
epi-acpcPNA	51	<20	27–28	41	<20	—	130
atfcPNA	53	<20	23–25	36	<20	<20	132
aocPNAc	46	—	<20–28	30	—	—	136
acbcPNA	66	<20	36–47	58	32	—	137
achcPNA	n.t.	<20	<20	<20	<20	—	137

^aSequences: PNA: Ac-GTAGATCACT-LysNH₂; apDNA: dAGTGX̲TCTAC; pDNA: dCATCTAGATG; apRNA: rAGUGX̲UCUAC; pRNA: dCAUCUAGAUG.

^bWithout C-terminal Lys.

^cWithout the N-terminal Ac group.