6265. MOPS

Nomenclature

CAS number: 1132-61-2
4-Morpholinepropanesulfonic acid; 3-(N-morpholino)propanesulfonic acid; N-(3-sulfopropyl)morpholine.
C7H15NO4S; mol wt 209.26.
C 40.18%, H 7.23%, N 6.69%, O 30.58%, S 15.32%.

Description and references

One of the zwitterionic amino acids known as “Good” buffers; active in the pH range of 6.5-8.0. Prepn: C. F. H. Allen et al., Anal. Chem. 37, 156 (1965); N. E. Good, S. Izawa, “Hydrogen Ion Buffers,” in Methods Enzymol. 24, 53-65 (1972). Temperature effects on pK: M. Sankar, R. G. Bates, Anal. Chem. 50, 1922 (1978); and pH: R. N. Roy et al., Cryo Letters 6, 139 (1985). Effects on “Lowry” protein determn: H. M. Himmel, W. Heller, J. Clin. Chem. Clin. Biochem. 25, 909 (1987). Uses as a biological buffer: E. P. Paques et al., Eur. J. Biochem. 107, 447 (1980); L. A. Sonna et al., J. Biol. Chem. 263, 6625 (1988).

Chemical structure

Properties

White powder, mp 283.5-284.5°. pKa 7.15. pKa2 (25°): 7.184; (37°): 7.041. ΔpKa/°C -0.013. Is not completely stable when autoclaved in the presence of glucose.

Use

Biological buffer.