Detail of "7561-25-3"

Reference

Proline iminopeptidase: chromatographic demonstration of a single form in human cultured skin fibroblasts, liver and kidney using a fluorimetric assay

Proline iminopeptidase: chromatographic demonstration of a single form in human cultured skin fibroblasts, liver and kidney using a fluorimetric assay. Butterworth, John; Priestman, David (Dep. Pathol., R. Hosp. Sick Child., Edinburgh EH9 1LF, UK). Clin. Chim. Acta, 137(2), 239-44 (English) 1984. CODEN: CCATAR. ISSN: 0009-8981. DOCUMENT TYPE: Journal CA Section: 7 (Enzymes) Section cross-reference(s): 13 A method for the detn. of proline iminopeptidase (EC 3.4.11.5) (I) in human tissues and cultured cells was developed, and a chromatog. investigation of the enzyme from these sources was made. I was detd. fluorometrically by reaction with Pro-Gly-Gly; Gly-Gly produced by this reaction was reacted with o-phthaldialdehyde to generate the fluorescent product. Glycine was not produced during the assay. Assays for I were carried out at pH 8.0 with 0.025 mM Mn2+ or at 8.5 without Mn2+; skin fibroblast I exhibited KM values for the substrate of 9.3 and 5.7 mM at pH 8.0 and 8.5, resp. Cultured skin fibroblasts and amniotic fluid cells had similar mean specific activities of I (159 and 150 nmol/min/mg protein, resp.). Human liver and kidney I levels were 164 and 414 nmol/min/mg protein, resp. I from human skin fibroblast, liver, and kidney eluted as a single peak from DEAE-cellulose, a single peak (mol. wt. 80,000) was also obsd. on Ultragel filtration. I from each source had pI = 5.3. Thus, a single form of I was present in these 3 sources.Except for chemicals metioned above, 7561-25-3 and 9025-40-5 are also used. .

Characterization of a peptidase from Lactococcus lactis ssp

Characterization of a peptidase from Lactococcus lactis ssp. cremoris HP that hydrolyses di- and tripeptides containing proline or hydrophobic residues as the aminoterminal amino acid. Baankreis, Ronald; Exterkate, Fred A. (Dep. Biophys. Chem., Netherlands Inst. Dairy Res., Ede 6710 BA, Neth.). Syst. 7561-25-3 and 9025-40-5 are cas registry numbers. These chemicals are also mentioned in this article. Appl. Microbiol., 14(4), 317-23 (English) 1991. CODEN: SAMIDF. ISSN: 0723-2020. DOCUMENT TYPE: Journal CA Section: 7 (Enzymes) Section cross-reference(s): 10, 17 An intracellular peptidase, showing highest catalytic activity towards di- and tripeptides contg. proline and to a lesser extent other hydrophobic residues as the amino-terminal amino acid, was purified from cell-free exts. of L. lactis ssp. cremoris HP. On SDS-PAGE the enzyme exhibited a mol. mass of 50 kDa. In HPLC gel filtration expts., an apparent mol. mass of approx. 110 kDa was obsd. The activity of the enzyme was inhibited by EDTA, dithiothreitol and some metal ions, but was not affected by PMSF, aprotinin or pepstatin. After inhibition with EDTA the activity could be restored by Co2+ and Mn2+. The optima for pH, temp. and NaCl concn. are 8.5, 37° and 100 mM resp. The Michaelis const. (Km) and Vmax for several proline-contg. di- and tripeptides were detd. .