Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biodegradable poly-L-lactic acid rods made of block-polymerized material (BP; molecular weight 550,000) and injection-moulded rods with high (SGI; molecular weight 121,000) and low (SGA, molecular weight 118,000) molecular orientation were compared 2, 4 and 6 weeks after incubation in enzyme solutions with high hydrolytic activity (esterase, alpha chymotrypsin and peptidase) and in buffer solution (TRIS buffer). The molecular weight, modulus of elasticity, bending strength (three-point bending test), and cyclic bending load to failure applied to the rods in a newly developed testing machine (1 Hz, maximum 100,000 cycles) were compared. The molecular weight of BP material decreased to 36% after 2 weeks, in contrast to the injection-moulded materials, in which it decreased only to 66% even after 6 weeks. The bending strength of all specimen decreased significantly faster in alpha chymotrypsin than in the other media (MANOVA, P < 0.001). SGI had a significantly higher bending strength than SGA, and SGA a higher strength than BP. There was no difference after incubation in the other two enzymatic solutions. BP lost 80% of its initial bending strength (140 N/mm2) after 6 weeks, and SGI and SGA (120 N/mm2) only 20%. Under permanent cyclic loading BP initially resisted 100,000 cycles with an applied cyclic load of 12.5 N/mm2, decreasing after 6 weeks to only 9,500 cycles, in contrast to SGI and SGA, which resisted to 46,000 cycles. There was, however, no relevant difference in the mechanical characteristics of the two injection-moulded rods. These results confirm that BP is degraded significantly faster than SGA and SGI.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Mechanical strength and chemical stability of biodegradable block-polymerized and injection molded poly-L-lactide in vitro]. 805 67

A series of potassium organotrifluoroborates were synthesized. Their stability to hydrolysis was determined in D2O, TRIS and phosphate buffer. It was found that in both D2O and TRIS buffers, these compounds are quite stable, whereas in phosphate buffer rapid hydrolysis occurs. Based on these results, a study was undertaken to determine whether potassium organotrifluoroborates can serve as protease inhibitors. It was found that potassium organotrifluoroborates increased inhibition by at least an order of magnitude over the corresponding boronates. Dixon plots showed that these compounds are reversible competitive inhibitors of alpha-chymotrypsin and trypsin. Based on 19F NMR, we speculate that they inactivate the enzymes as a result of the formation of hydrogen-bonds between fluorine atoms of the inhibitors and the serine protease.
 ...
PMID:Noncovalent inhibition of the serine proteases, alpha-chymotrypsin and trypsin by trifluoro(organo)borates. 1573 82

Alginate has potential as a matrix for controlled delivery of protein-based drugs that require site-specific long-term delivery. In the current work albumin, lysozyme and chymotrypsin were encapsulated into alginate microspheres using a novel method that involved soaking the microspheres in a protein-containing NaCl solution. This was followed by recrosslinking with calcium chloride. High pI proteins also appeared to physically crosslink the sodium alginate which resulted in more sustained release. Release was affected by the nature of the releasate solution. In TRIS buffered saline, the high pI proteins chymotrypsin and lysozyme showed sustained release lasting over 150 h. Release into 0.15% NaCl led to relatively constant release of lysozyme and chymotrypsin over more than 2000 h; reduction of the releasate volume lengthened the lysozyme release to greater than 8 months. Released lysozyme was shown to remain active for at least 16 days, in some cases with activity greater than 100% of the active control. This encapsulation technique can therefore be used to rapidly load alginate microspheres with proteins, with high isoelectric point proteins showing particular promise. Furthermore, the interactions between the high pI proteins and the alginate gel could potentially be exploited to generate new protein delivery systems.
 ...
PMID:Extended release of high pI proteins from alginate microspheres via a novel encapsulation technique. 1715 84