Title: MOPS
CAS Registry Number: 1132-61-2
CAS Name: 4-Morpholinepropanesulfonic acid
Additional Names: 3-(N-morpholino)propanesulfonic acid; N-(3-sulfopropyl)morpholine
Molecular Formula: C7H15NO4S
Molecular Weight: 209.26
Percent Composition: C 40.18%, H 7.23%, N 6.69%, O 30.58%, S 15.32%
Literature 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-Lett. 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).
Properties: White powder, mp 283.5-284.5°. pKa 7.15. pKa2 (25°): 7.184; (37°): 7.041. DpKa/°C -0.013. Is not completely stable when autoclaved in the presence of glucose.
Melting point: mp 283.5-284.5°
pKa: pKa 7.15; pKa2 (25°): 7.184; (37°): 7.041; pKa/°C -0.013
Use: Biological buffer. |