Naslov
A novel enzymatic acitivity from guinea pig serum

Autori
Krstanović, Marina ; Halassy Špoljar, Beata ; Frkanec, Ruža ; Šporec, Vesna ; Vranešić, Branka ; Ljevaković, Đurđica ; Tomašić, Jelka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Drugi hrvatski kongres farmacije s međunarodnim sudjelovanjem, Knjiga sažetaka / Jandrijević-Mladar Takač, M; Jurišić, R; Vuković, J - Zagreb : Farmaceutsko-biokemijski fakultet Sveučilišta u Zagrebu, 2001, 133-133

Skup
Drugi hrvatski kongres farmacije s međunarodnim sudjelovanjem

Mjesto i datum
Cavtat, Hrvatska, 31.05.2001. - 03.06.2001

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Sažetak
Enzymes are important tools in the preparation of new pharmacologically active substances because they can act as stereo-, regio- and chemoselective catalysts. Here we report on a novel enzymatic activity observed in the guinea pig serum that seems to be specific for cleaving alternating L- and D- amino acids bond that are found in bacterial peptidoglycans. We have shown previously that N-acetylmuramyl-L-alanine amidase1 present in mammalian blood cleaves peptidoglycan monomer (PGM, PLIVA) into dissacharide and pentapeptide portion. PGM is the basic repeating unit of Brevibacterium divaricatum cell wall peptidoglycan. It possesses many beneficial characteristics that are optional for a pharmaceutical product: completely defined chemical structure, that can be consistently produced; it is non-toxic, apyrogenic and water soluble; can be lyophilised without the loss of biological activity; stable over a long period of time. It exhibits strong immunomodulating, antitumor and antimetastatic activity2. Recently we discovered the new enzymatic activity in the guinea pig serum that cleaves alanine from the pentapeptide portion. Enzyme was partially purified on DEAE-Sepharose FF and enzymatic reaction was followed by thin layer chromatography and HPLC using pentapeptide as a substrate. Mass spectroscopy of the tetrapeptide suggested that alanine was cleaved from the amino terminus of the pentapeptide. To further prove this observation we analysed the alanine with stereospecific enzymes (L- and D-amino acid oxidase, AAO). It was oxidised only by L-AAO what was consistent with mass spectroscopy results. In addition we tested the specificity of novel enzyme using different derivatives of PGM3,4 and different peptides having protected or free amino group of terminal alanine. All results indicated that the novel enzyme could be L,D-aminopeptidase. (1Valinger et al. Biochim. Biophys. Acta 701 (1982) 63-71,2Tomašić et al. Vaccine 18 (2000) 1236-1243, 3Hršak et al. Imunotherapy of infections (1994) 249-257, 4Vranešić et al. Helv. Chim. Acta 76 (1993) 1752-1757)

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

POVEZANOST RADA