Methanogens are generally found in anaerobic, reduced environments where substrates are either provided by other anaerobic microorganisms or from geological sources.
In the present experiment, the activity of serine proteinases was not detected in secretions even by using various fluorogenic synthetic substrates for serine proteinases.
Similarly, concentrations of lactate are higher within the caeca and colons of ruminants given feeds high in readily fermentable substrates, particularly grains [11, 14].
Stereospecificity is a crucial feature of biology that permits the highly selective recognition of substrates by their enzymes, and hormones and neurotransmitters by receptors.
Structural kinetics of the allosteric transition of aspartate transcarbamylase produced by physiological substrates.
A variety of substrates such as active metal surfaces, clay minerals or zeolites could act as surface catalysts.
The activities detected with all substrates used were decreased by treatment with cysteine proteinase inhibitors.
Thus, there are large problems in seeing natural substrates crystallographically.
