YS-galactosidase

Weit From the heterozygote knock-in animals that are labelled with yS galactosidase and show where the melanopsin axons go, there are some hints that a small number of fibres actually by-pass the SCN and go towards the SPZ. This hasn t been worked out yet, but there is an idea that both the SPZ projection and the SCN projection may be melanopsinergic. There could be differential projections. 

MPS IV B Morquio B Spectrum of severity as in IV A yS-Galactosidase Keratan sulfate... 

When the accessible concentration range of glycal [A] c Kj and kpg- c khydr as for ) -D-galactosidase from E. coli, this reduces to k (1 + [S]/ Kp,) = (kp /K,0 [A] + khydf. The rate constant k yj, for the addition of water has to be measured separately, by the appearance of the 2-deoxy-o-hexose. With )S-D-galactosidase from E. and yS-D-glucosidase from... 

The fact that ) -D-galactosidase from Escherichia coli is inactivated more rapidly in the absence of Mg than in its presence can be taken as evidence that the activation of the triazene 38, that is, formation of )5-D-galactosyl-methyldiazonium ion, proceeds without acid catalysis, because Mg is required for the proton-assisted catalysis of yS-D-galactoside hydrolysis by this enzyme.Additional evidence for the absence of acid catalysis in the de-... 

In order to account for the inability of many enzymes to bind the protonated form of the basic inhibitors or permanently cationic ones better than uncharged analogs (for example, yS-o-galactosidase from E. coli, and P-v>-glucosidase from almonds), it was proposed that the enzyme could proton-ate the inhibitor at the active site by a cationic acid (for example, protonated histidine). If proton transfer cannot occur, the attractive forces due to the carboxylate would be canceled by the repulsion from the cationic acid. Experimental evidence for this proposal is, however, still lacking. In fi-D-gn-lactosidase from E. coli, a tyrosine is presumed to be responsible for the protonation of substrates. ... 

Broadhead J, Ruan SK, Rhodes CT. The effect of process and formulation properties on the properties of spray dried 3-galactosidase. J Pharm Pharmacol 1994 46 458-467. Kim CK, Soon YS. Development of digoxin dry elixir as a novel dosage form using a spray-drying technique. J Microencap 1995 12(5) 547-566. 

The mechanisms of hydrolysis by a- and yS-D-galactosidases, and the antibody-mediated activation of yS-o-galactosidase mutants and complementing fragments have been discussed. 

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