Extracellular nucleases of Lysobacter enzymogenes: purification and characterization of a ribonuclease

1981 ◽  
Vol 27 (10) ◽  
pp. 1080-1086 ◽  
Author(s):  
R. G. vonTigerstrom
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polypeptide Chain ◽  
Maximum Activity ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Lysobacter Enzymogenes ◽  
Base Specificity

The ribonuclease of Lysobacter enzymogenes is one of two major extracellular nucleolytic enzymes produced by the organism. The enzyme was purified 560-fold and appeared to be free of contaminating proteins and interfering enzymes. The Lysobacter RNAase consists of one polypeptide chain with a molecular weight of 46 000 – 47 000. The enzyme was most active at pH 8.0–8.5 and in the presence of Mg2+. Approximately 45% of the maximum activity was obtained in the presence of Ca2+, whereas little or no activity was obtained in the presence of Mn2+ or without divalent metal ions. RNA, poly(A), and poly(C) served as substrates but DNA was not hydrolysed. High molecular weight RNA was degraded by the RNAase to short oligonucleotides with 5′-phosphate ends and there was no apparent base specificity.

Purification and Characterization of a High-Molecular-Weight Protease, Ingensin, from Human Placenta

1986 ◽  
Vol 99 (6) ◽  
pp. 1605-1611 ◽  
Author(s):  
Michio NOJIMA ◽  
Shoichi ISHIURA ◽  
Takeshi YAMAMOTO ◽  
Teruaki OKUYAMA ◽  
Hiroshi FURUYA ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Human Placenta ◽  
Purification And Characterization ◽  
High Molecular Weight Protease

Purification and Characterization of Three Extracellular Proteinases Produced by Pseudomonas fluorescens INIA 745, an Isolate from Ewe's Milk

1999 ◽  
Vol 62 (5) ◽  
pp. 543-546 ◽  
Author(s):  
J. FERNÁNDEZ ◽  
A. F. MOHEDANO ◽  
P. GAYA ◽  
M. MEDINA ◽  
M. NUÑEZ
Keyword(s):  
Pseudomonas Fluorescens ◽  
Culture Medium ◽  
Inhibitory Effect ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Ph Optimum ◽  
Extracellular Proteinases ◽  
Ewe's Milk

Three proteinases were isolated from culture medium of Pseudomonas fluorescens INIA 745 and purified to homogeneity by a combination of Phenyl-Sepharose, DEAE-Sepharose, and Sephadex G-100 chromatography. Optimal temperature for enzymatic activity was 45°C for all three proteinases. The pH optimum of proteinases I and II was found to be 7.0, while that of proteinase III was 8.0. Divalent metal ions like Cu2+, Co2+, Zn2+, Fe2+, and Hg2+ were inhibitory to proteinase activity while Ca2+, Mg2+, and Mn2+ had little or no inhibitory effect. The three enzymes were strongly inhibited by EDTA and 1,10-phenantroline and partially by cysteine. The three enzymes are metalloproteinases since they were inhibited by chelators and reactivated by Co2+, Mn2+, Cu2+, and Zn2+. The Km values of proteinases I, II, and III for casein were calculated to be 3.2, 2.6, and 5.2 mg/ml, respectively. Proteinases II and III rapidly degraded β-casein, with preference to αs1-casein, whereas proteinase I hydrolyzed both casein fractions at a slow rate.

Purification and characterization of a novel high molecular weight exotoxin produced by red tide phytoplankton,Alexandrium tamarense

2008 ◽  
Vol 22 (6) ◽  
pp. 405-415 ◽  
Author(s):  
Yasuhiro Yamasaki ◽  
Daisuke Katsuo ◽  
Seiichiro Nakayasu ◽  
Cristina Salati ◽  
JingJing Duan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Red Tide ◽  
Alexandrium Tamarense ◽  
Purification And Characterization
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