R K Harrison

Learn More
Substrate specificities, as reflected in kc/Km, were determined for the peptidyl prolyl cis-trans isomerase activities of cyclophilin and the FK-506 binding protein (FKBP). The substrates investigated were peptides of the general structure Suc-Ala-Xaa-Pro-Phe-p-nitroanilide, where Xaa = Gly, Ala, Val, Leu, Phe, His, Lys, on Glu. While kc/Km for(More)
An extensive study of the requirements for effective binding of N-carboxyalkyl peptides to human stromelysin, collagenase, and to a lesser extent, gelatinase A has been investigated. These efforts afforded inhibitors generally in the 100-400 nM range for these matrix metalloproteinases. The most significant increase in potency was obtained with the(More)
Cyclophilin, the cytosolic binding protein for the immunosuppressive drug cyclosporin A, has recently been shown to be identical with peptidyl prolyl cis-trans isomerase [Fischer, G., Wittmann-Liebold, B., Lang, K., Kiefhaber, T., & Schmid, F.X. (1989) Nature 337, 476; Takahashi, N., Hayano, T., & Suzuki, M. (1989) Nature 337, 473]. To provide a mechanistic(More)
To probe the specificity of the metalloendoproteinase stromelysin toward peptide substrates, we determined kc/Km values for the stromelysin-catalyzed hydrolyses of peptides whose design was based loosely on the structure of a known SLN substrate, substance P (Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-MetNH2, hydrolysis at Gln-Phe, kc/Km = 1700 M-1 s-1).(More)
Carboxyalkyl peptides containing a biphenylylethyl group at the P1' position were found to be potent inhibitors of stromelysin-1 (MMP-3) and gelatinase A (MMP-2), in the range of 10-50 nM, but poor inhibitors of collagenase (MMP-1). Combination of a biphenylylethyl moiety at P1', a tert-butyl group at P2', and a methyl group at P3' produced orally(More)
To probe the mechanism of stromelysin (SLN)-catalyzed peptide hydrolysis, we determined the pH dependence of kc/Km and solvent deuterium isotope effects on kc and kc/Km. pH dependencies of kc/Km were determined for the SLN-catalyzed hydrolysis of three peptides: Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Nle-NH2,Arg-Pro-Ala-Pro-Gln-Gln- Phe-Phe -(More)
To probe the substrate specificity of the human metalloproteinase stromelysin (SLN), we determined values of kc/Km for the SLN-catalyzed hydrolysis of substance P (Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-MetNH2; SP; kc/Km = 1790 +/- 140 M-1 s-1), 15 analogues of SP, and 17 other peptides. We found a remarkably narrow substrate specificity for SLN: while SP(More)
Nitric oxide synthase (EC 1.14.23) substrate analog inhibitors NG-monomethyl-L-Arg, NG-nitro-L-Arg, NG-nitro-L-Arg methyl ester, and aminoguanidine were examined as potential inhibitors of rat liver arginase (EC 3.5.3.1). NG-nitro-L-Arg was found to inhibit arginase catalyzed conversion of L-Arg to L-Orn at pH 7.5 with an IC50 = 27.2 +/- 4.3 mM, compared to(More)
We present complexity measurements from ECG signals during ventricular brillation (VF) using the Gaussian kernel algorithm. Ten ECG data sets of early VF among 53 pig subjects are selected for such analysis. A single test uses a segment of 33.33 seconds and 15 measurements are made on each ECG trace over sliding windows with a skipping length of 10 seconds.(More)
A search for low molecular weight peptide substrates for the metalloendoproteinase, human fibroblast stromelysin, resulted in the discovery that substance P (Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-Gly-Leu-Met-NH2) is a substrate for this enzyme and is cleaved exclusively at the Gln6-Phe7 bond. On the basis of this observation, a semicontinuous HPLC-based assay was(More)
  • 1