Using molecular graph theory we studied the binding of NSFRY-NH and 12 related pentapeptide amides to Cu(II) as a model system for atrial natriuretic factor (ANF) peptide interactions with copper. Linear regression models based on the valence connectivity index of the 3 order ( ) reproduced experimental stability constants (log β) for 1N, 2N, 3N, and 4N coordinated complexes with the standard error of 0.30-0.39 log β units. We developed separate models for seven tyrosinic (N=28) and five non-tyrosinic peptides (N=20), and a common model for both kinds of peptides (N=48) with an indicator (dummy) variable. The results indicate additional aromatic stabilisation in 4N complexes due to metal cation-π interactions with tyrosine but not with the phenylalanine residue. We have also amended the log K and log K* values to correct miscalculations published by Janicka-Klos et al. in 2013 Služeći se teorijom molekularnih grafova istraživali smo vezivanje NSFRY-NH i 12 srodnih pentapetidnih amida za Cu(II) kao modelnog sustava za interakciju bakra s peptidnom molekulom atrijalnog natriuretičkog faktora (ANF). Modeli linarne regresije temeljeni na valencijskom indeksu povezanosti trećega reda ( ) reproducirali su eksperimentalnu konstantu stabilnosti (log β) za komplekse koordinacije 1N, 2N, 3N i 4N sa standardnom pogreškom u rasponu od 0,30 do 0,39 log β jedinica. Razvili smo odvojene modele za sedam tirozinskih (N=28) i pet netirozinskih (N=20) peptida te skupni model s indikatorskom varijablom za obje vrste peptida (N=48). Rezultati upućuju na dodatnu aromatsku stabilizaciju u kompleksima vrste 4N zbog interakcija kationa s π-orbitalama tirozinskog ostatka, ali ne i fenilalaninskoga. Ispravili smo i pogrešne vrijednosti log K i log K* nastale omaškom u radu Anne Janicka-Klos i sur. 2013.