| dc.contributor.author |
Georgalaki, MD |
en |
| dc.contributor.author |
Papdelli, M |
en |
| dc.contributor.author |
Anastasiou, R |
en |
| dc.contributor.author |
Kalantzopoulos, G |
en |
| dc.contributor.author |
Tsakalidou, E |
en |
| dc.date.accessioned |
2014-06-06T06:45:08Z |
|
| dc.date.available |
2014-06-06T06:45:08Z |
|
| dc.date.issued |
2002 |
en |
| dc.identifier.issn |
00237302 |
en |
| dc.identifier.uri |
http://62.217.125.90/xmlui/handle/123456789/2263 |
|
| dc.relation.uri |
http://www.scopus.com/inward/record.url?eid=2-s2.0-0036881992&partnerID=40&md5=b965afdcc4385eb313e7a4894c32d813 |
en |
| dc.subject.other |
Amino acids |
en |
| dc.subject.other |
Bacteria |
en |
| dc.subject.other |
Chromatography |
en |
| dc.subject.other |
Filtration |
en |
| dc.subject.other |
Genes |
en |
| dc.subject.other |
Molecular weight |
en |
| dc.subject.other |
Organic acids |
en |
| dc.subject.other |
Purification |
en |
| dc.subject.other |
Gel filtration |
en |
| dc.subject.other |
Enzymes |
en |
| dc.subject.other |
Bacteria (microorganisms) |
en |
| dc.subject.other |
Streptococcus |
en |
| dc.subject.other |
Streptococcus macedonicus |
en |
| dc.title |
Purification and characterization of the X-prolyl-dipeptidyl aminopeptidase (pepX) from Streptococcus macedonicus and cloning of the pepX gene |
en |
| heal.type |
journalArticle |
en |
| heal.publicationDate |
2002 |
en |
| heal.abstract |
The X-prolyl-dipeptidyl aminopeptidase from Streptococcus' macedonicus ACA-DC 191 was purified by anion exchange and hydrophobic interaction chromatography. A single band of a molecular mass of about 84 000 g·mol-1 appeared in SDS-PAGE; by gel filtration it was shown that the native enzyme was dimeric. The enzyme showed optimum activity on glycyl-prolyl-4-nitroanilide at pH 7.0, with a KM = 0.42 mmol·L-1 and a Vmax = 12.8 μmol·mg-1·min-1. It was active over a temperature range of 10-60 °C. Over 60 °C, the enzyme activity declined rapidly. The peptidase was completely inactivated by PMSF, DTNB and Cu2+ while metal chelators had no effect on enzyme activity. By using the PCR technique with synthetic primers, the pepX gene was amplified, cloned and sequenced. This 2 289 nucleotide gene encodes a protein of 763 amino acids with a molecular mass of 86 866 g·mol-1. The deduced amino acid sequence analysis of the pepX gene shows a high identity with PepX enzymes from other lactic acid bacteria and contains a motif around the active site serine (G-K-S-Y-L-G) that is well conserved among the PepX enzymes. |
en |
| heal.journalName |
Lait |
en |
| dc.identifier.issue |
6 |
en |
| dc.identifier.volume |
82 |
en |
| dc.identifier.spage |
657 |
en |
| dc.identifier.epage |
671 |
en |