Table 1.

The table illustrates the various trypsin digestion products.

Name of the specie	MW (Da)	pI	Cleavage site	Description of the digestion product	Tag
desoctaNGF−YBBR-2 C-Term	13202.8	8.27	R +9; L +128	Without the first 9 aa at the N-terminus and 2 aa at the C-terminus	Yes
NGF−YBBR -2 C-Term	14252.6	8.56	R −1; L +128	Without 2 aa at the C-terminus	Yes
NGF−Tag YBBR	13261.3	8.81	R −1; R +118	Without 11 aa at the C-terminus	No
NGF−YBBR +R N-Term; -2 C-Term	14408.4	8.8	K −2; L +128	Plus the arginine at the N-terminus and without 2 aa at the C-terminus	Yes
NGF+R N-Term -Tag YBBR	13417.1	9.0	K −2; R +118	Plus the arginine at the N-terminus and without 11 aa at the C-terminus	No

The first reported specie, lacking the first 9 amino acids, is here termed “DesoctaNGF” because it resembles the naturally occurring desocta form reported for murine NGF (Fahnestock, 1991). The other species are characterized by the lack of two amino acids or of the entire YBBR tag at the C-terminus (-2 C-Term or -Tag YBBR). The species that contains the arginine at the N-Terminus are also shown (+R N-Term). The second and third columns show the molecular weights (Dalton) and the theoretical isoelectric point of the digested species. The amino acids numeration adopted is in accordance to the literature (Paoletti et al., 2009).