Abstract: Two sweet proteins named mabinlin I and mabinlin II (Ma I , Ma I) with MW. 11.6 kD and 10.4 kD respectively had been isolated. By using Edman degradation and the method of reversed phase HPLC identification of PTH-aa, it were found that the N-terminuses of both proteins are blocked because of cyclization of pyroglutamic acid. The pyrrolidone was opened by treatment with 1 mol/l HCl-methanol at 35°C for 24 h. The eight amino acid sequence of N-terminal peptide was pyroglutamic acid-Pro-Arg-Gly-Pro-Ala-Leu-Arg-in both proteins. Dynamic analysis of the enzymatic products by carboxypeptidasc showed that the amino acid sequence of C-terminal peptide is -Phe-Gln-Leu-Ala-Scr in Ma II , and -Phe Gin-Leu-Ala in Ma II . the result means that even though the Ma II lack a Ser residue at C-terminus the main difference of the two sweet proteins is not- in the amino acid sequences of both C- and N- terminal regions.

Key words: Sweet protein