Multinuclear magnetic resonance studies and molecular modeling on serine protease active centers

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:6871108

Adebodun, F A

Trypsin, chymotrypsin, and subtilisin were inhibited with diisopropylfluorophosphate (DIFP)-an irreversible inhibitor of serine proteases, in a reaction that placed the phosphorus atom at the active center. Using Gd(III) as a relaxation probe, the relaxation enhancement for each enzyme complex was monitored by {sup 31}P NMR. The distance between the phosphorus atom at the active site and the calcium binding site was calculated from the Solomon-Bloembergen equations. The determined distances were used to find Ca(II) binding ligands through molecular modeling of the enzymes. {sup 113}Cd NMR was used to characterize Ca(II) binding sites in trypsin, {alpha}-chymotrypsin, and subtilisin. {sup 31}P NMR studies were performed on mono- and diisopropylphosphoryl derivatives of trypsin, {alpha}-chymotrypsin, and subtilisin. Questions addressed included the pK{sub a} of the active center Asp... His... Ser triad in both species. The action of PAM (pyridine-2-aldoxime methiodide) on the inactivated enzymes, was also determined by {sup 31}P NMR. {sup 11}B NMR studies were performed on phenylboronic acid (PBA) and 3,5-bis-trifluoromethylphenylboronic acid (BTFPBA) in the presence and absence of {alpha}-chymotrypsin.

• Research Organization: Rutgers-the State Univ., New Brunswick, NJ (USA)
• OSTI ID: 6871108
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
SERINE PROTEINASES
MOLECULAR STRUCTURE
BORON 11
CADMIUM 113
CALCIUM COMPOUNDS
ENZYME INHIBITORS
LIGANDS
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
PHOSPHORUS 31
RECEPTORS
TRACER TECHNIQUES
TRYPSIN
ALKALINE EARTH METAL COMPOUNDS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BORON ISOTOPES
CADMIUM ISOTOPES
ENZYMES
EVEN-ODD NUCLEI
HYDROLASES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MEMBRANE PROTEINS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HYDROLASES
PHOSPHORUS ISOTOPES
PROTEINS
RADIOISOTOPES
RESONANCE
SPECTRA
STABLE ISOTOPES
YEARS LIVING RADIOISOTOPES
550201* - Biochemistry- Tracer Techniques