Characterization of the phosphoserine of pepsinogen using /sup 31/P nuclear magnetic resonance: corroboration of X-ray crystallographic results

Journal Article · Tue Oct 21 00:00:00 EDT 1986 · Biochemistry; (United States)

OSTI ID:6522427

Williams, S P; Bridger, W A; James, M N.G.

The endogenous phosphoserine residue in porcine pepsinogen has been titrated with use of phosphorus-31 nuclear magnetic resonance (/sup 31/P NMR). It has an observed pK/sub a/sub 2// of 6.7 and a narrow line width (approx. =10 Hz). The phosphate can be readily removed by an acid phosphatase from potato; however, it is resistant to hydrolysis by several alkaline phosphatases. The X-ray crystal structure of porcine pepsinogen at 1.8-A resolution shows a rather weak and diffuse region of electron density in the vicinity of the phosphorylated serine residue. This suggests considerable dynamic mobility or conformational disorder of the phosphate. In order to define more fully this behavior the NMR data have been used to corroborate these crystallographic results. All these physical data are consistent with a highly mobile phosphoserine residue on the surface of the zymogen and freely exposed to solvent. In addition, certain properties of this phosphoserine moiety on pepsinogen are similar to those of one of the phosphorylated residues of ovalbumin. The possible significance of this is discussed.

• Research Organization: Univ. of Alberta, Edmonton
• OSTI ID: 6522427
• Journal Information: Biochemistry; (United States), Vol. 25:21
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
59 BASIC BIOLOGICAL SCIENCES
PEPTIDE HYDROLASES
MOLECULAR STRUCTURE
SERINE
NUCLEAR MAGNETIC RESONANCE
X-RAY DIFFRACTION
ACID PHOSPHATASE
CRYSTALLOGRAPHY
PEPSIN
PHOSPHORUS 31
PHOSPHORYLATION
SWINE
ACID PROTEINASES
AMINO ACIDS
ANIMALS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
COHERENT SCATTERING
DIFFRACTION
DOMESTIC ANIMALS
ENZYMES
ESTERASES
HYDROLASES
HYDROXY ACIDS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHOSPHATASES
PHOSPHORUS ISOTOPES
RESONANCE
SCATTERING
STABLE ISOTOPES
VERTEBRATES
550602* - Medicine- External Radiation in Diagnostics- (1980-)
550201 - Biochemistry- Tracer Techniques