Phosphorus-31 NMR of covalent phosphorylated derivatives of. alpha. -chymotrypsin

Journal Article · Tue Mar 07 04:00:00 EST 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00431a013· OSTI ID:5545890

Gorenstein, D G; Shah, D; Chen, R; Kallick, D ^[1]

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1. Purdue Univ., West Lafayette, IN (USA)

The structures of various covalent phosphorylated derivatives of {alpha}-chymotrypsin ({alpha}-CT) have been studied by {sup 31}P NMR spectroscopy. Diisopropylphosphoryl-{alpha}-chymotrypsin ({alpha}-DIPCT) shows a single {sup 31}P signal at ca. 0.0 ppm (pH 4). At low pH, the {sup 31}P NMR spectrum of {alpha}-DIPCT gradually changed with the appearance of one or two additional peaks. The ratio of the peaks varied with pH, time, and concentration. One of these two new downfield peaks (both at ca. 2.0 ppm) has been previously identified. A new additional downfield signal, separate from the {alpha}-MIPCT signal, is attributed to a dimer of the phosphorylated {alpha}-DIPCT. Phosphorylation of the enzyme with diphenyl chlorophosphate yields a monophenylphosphoryl-{alpha}-chymotrypsin ({alpha}-MPPCT) that also showed a single {sup 31}P signal at -2.1 ppm (pH 7). However, the spectrum did not change as a function of pH, incubation time, or concentration. Comparison of the {sup 31}P chemical shifts of the native and denatured phosphorylated derivatives of {alpha}-chymotrypsin suggests changes in the conformation about the P-O ester bonds are at least partially responsible for the various {sup 31}P chemical shift differences.

• OSTI ID: 5545890
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 28:5; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
CHEMICAL BONDS
CHEMICAL REACTIONS
CHEMICAL SHIFT
CHYMOTRYPSIN
CONFORMATIONAL CHANGES
DERIVATIZATION
ENZYMES
HYDROLASES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
PEPTIDE HYDROLASES
PH VALUE
PHOSPHORUS 31
PHOSPHORUS ISOTOPES
PHOSPHORYLATION
RESONANCE
SERINE PROTEINASES
STABLE ISOTOPES