Aminopeptidase Activity in Lakes of Differing Eutrophication

1991 ◽  
pp. 155-164 ◽  
Author(s):  
Timothy R. Jacobsen ◽  
Hakumat Rai
Keyword(s):  
Aminopeptidase Activity

Quantification of small-scale heterogeneity in aquatic aminopeptidase activity

2020 ◽  
Vol 84 ◽  
pp. 127-140
Author(s):  
BM Gaas ◽  
JW Ammerman
Keyword(s):  
Chlorophyll Fluorescence ◽  
Leucine Aminopeptidase ◽  
Hudson River ◽  
Aminopeptidase Activity ◽  
Small Scale ◽  
Analysis Instrument ◽  
Sequential Samples ◽  
Degree Of Confidence ◽  
The Mean ◽  
Hydrolysis Of

Leucine aminopeptidase (LAP) is one of the enzymes involved in the hydrolysis of peptides, and is sometimes used to indicate potential nitrogen limitation in microbes. Small-scale variability has the potential to confound interpretation of underlying patterns in LAP activity in time or space. An automated flow-injection analysis instrument was used to address the small-scale variability of LAP activity within contiguous regions of the Hudson River plume (New Jersey, USA). LAP activity had a coefficient of variation (CV) of ca. 0.5 with occasional values above 1.0. The mean CVs for other biological parameters—chlorophyll fluorescence and nitrate concentration—were similar, and were much lower for salinity. LAP activity changed by an average of 35 nmol l-1 h-1 at different salinities, and variations in LAP activity were higher crossing region boundaries than within a region. Differences in LAP activity were ±100 nmol l-1 h-1 between sequential samples spaced <10 m apart. Variogram analysis indicated an inherent spatial variability of 52 nmol l-1 h-1 throughout the study area. Large changes in LAP activity were often associated with small changes in salinity and chlorophyll fluorescence, and were sensitive to the sampling frequency. This study concludes that LAP measurements in a sample could realistically be expected to range from zero to twice the average, and changes between areas or times should be at least 2-fold to have some degree of confidence that apparent patterns (or lack thereof) in activity are real.

Aminopeptidase activity of staining fungi grown in artificial media

1995 ◽  
Vol 17 (4) ◽  
pp. 347-352 ◽  
Author(s):  
S. Banerjee ◽  
C. Breuil ◽  
D.L. Brown
Keyword(s):  
Aminopeptidase Activity

Aminopeptidase activity in the postmortem brain of human heroin addicts

2005 ◽  
Vol 46 (3) ◽  
pp. 213-219 ◽  
Author(s):  
G. Larrinaga ◽  
J. Gil ◽  
J.J. Meana ◽  
F. Ruiz ◽  
L.F. Callado ◽  
...  
Keyword(s):  
Postmortem Brain ◽  
Aminopeptidase Activity ◽  
Heroin Addicts

“In vivo” amplification of biological activity of tetragastrin by amino acid hydroxamates

1984 ◽  
Vol 4 (12) ◽  
pp. 1009-1015 ◽  
Author(s):  
J. P. Bali ◽  
H. Mattras ◽  
A. Previero ◽  
M. A. Coletti-Previero
Keyword(s):  
Biological Activity ◽  
Amino Acid ◽  
Aromatic Amino Acid ◽  
Aminopeptidase Activity ◽  
Proteolytic Degradation ◽  
Short Peptides ◽  
Rat Blood ◽  
Active Peptides

Rat blood was shown to contain an aminopeptidase which rapidly hydrolyses short peptides containing an aromatic amino acid as N-terminal residue. Using tetragastrin (Trp-Met-Asp-PheNH 2) as substrate, we showed that some amino acid hydroxamates inhibit rat aminopeptidase activity ‘in vitro’ in the following order: HTrpNHOH > HPheNHOH ≫ HAIaNHOH. The same hydroxamates markedly enhanced the biological activity of tetragastrin ‘in vivo’. The amplification of the secretory effect, correlated with the amount of the hydroxamate used, strongly suggests that these compounds can stabilize a number of active peptides in vivo by inhibiting their proteolytic degradation.

scholarly journals An aminopeptidase activity in bovine pituitary secretory vesicles that cleaves the N-terminal arginine from β-lipotropin60-65

FEBS Letters ◽  
1984 ◽  
Vol 175 (1) ◽  
pp. 135-139 ◽  
Author(s):  
Harold Gainer ◽  
James T. Russell ◽  
Y.Peng Loh
Keyword(s):  
Aminopeptidase Activity ◽  
Secretory Vesicles

Decrease in cytosolic Aspartyl-aminopeptidase but not in Alanyl-aminopeptidase activity in the frontal cortex of the aged rat

1995 ◽  
Vol 687 (1-2) ◽  
pp. 211-213 ◽  
Author(s):  
Concepcion Iribar ◽  
M.Jose Esteban ◽  
J.Manuel Martinez ◽  
Jose M. Peinado
Keyword(s):  
Frontal Cortex ◽  
Aminopeptidase Activity ◽  
Aged Rat ◽  
Alanyl Aminopeptidase ◽  
Aspartyl Aminopeptidase

Partial characterization of cheese-ripening proteinases produced by the yeastKluyveromyces lactis

1983 ◽  
Vol 50 (4) ◽  
pp. 469-480 ◽  
Author(s):  
Paul A. Grieve ◽  
Barry J. Kitchen ◽  
John R. Dulley ◽  
John Bartley
Keyword(s):  
Molecular Weight ◽  
Kluyveromyces Lactis ◽  
Apparent Molecular Weight ◽  
Aminopeptidase Activity ◽  
Carboxypeptidase Y ◽  
Casein Hydrolysis ◽  
Cheese Ripening ◽  
Caseinolytic Activity ◽  
Proteinase A

SUMMARYAn extract ofKluyveromyces lactis416 and a β-galactosidase preparation (Maxilact 40000) contaminated with proteinase, showed similar pH profiles of caseinolytic activity. Similar modes of casein hydrolysis (κ-, > αs-, ≥ β-) were observed at pH 5·0 (the pH of Cheddar cheese), without detection of bitterness. The contaminated Maxilact preparation contained similar proteinase types to those detected in an autolysate ofK. lactis. Both the autolysate and the Maxilact preparation contained acid endopeptidase (proteinase A), serine endopeptidase (proteinase B) and serine exopeptidase (carboxypeptidase Y) activities. Some aminopeptidase activity was also detected in both preparations. There were some differences in apparent molecular weight and charge properties between proteinase A and B and carboxypeptidase Y from the 2 proteinase sources.

Sign in / Sign up

Export Citation Format

Share Document