Solid-phase synthesis and crystallization of [Asn22, Gln25, Asn26]-A-chain-[Asn49, Glu50]-B-chain-monellin, an analogue of the sweet protein monellin.
The sweet protein monellin consists of two noncovalently associated polypeptide chains, the A chain of 44 amino acid residues and the B chain of 50 residues. The [Asn22, Gln25, Asn26]-A chain, an anologue of the A chain, was synthesized by the stepwise Fmoc-solid-phase method in an overall yield of 13.4%. The synthetic A chain analogue was combined with the [Asn49, Glu50]-B chain, which was left over from a previous work, to give [Asn22, Gln25, Asn26]-A-chain-[Asn49,Glu50]-B-chain-monellin in a yield of 26.2%. This synthetic monellin analogue was approximately 550 times sweeter than sucrose. Changing the carboxyl groups of Asp22, Glu25, and Asp26 of the A chain to amide groups significantly decreased the sweetness potency. Crystallization was performed by a vapor diffusion method.
Central Research Laboratories, Ajinomoto Co., Inc., Kawasaki, Japan.
M
M
Kohmura
N
N
Nio
Y
Y
Ariyoshi
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D003460:Crystallization; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000138:chemical synthesis* / Q000737:chemistry; D016339:Spectrometry, Mass, Fast Atom Bombardment
D010940:Plant Proteins; C002541:monellin protein, Dioscoreophyllum cumminsii; C069034:monellin, Asn(22)-Gln(25)-Asn(26)-A-chain-Asn(49)-Glu(50)-B-chain-