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)

A procedure is described to isolate the major outer membrane protein (protein I) from Neisseria gonorrhoeae in large quantities. The method involves precipitation of protein I by hexadecyltrimethylammonium bromide (CTB) at low ionic strength. CTB is lethal for the gonococci and solubilizes most other proteins. Protein I is brought into solution by raising the ionic strength, and the nucleic acids are subsequently removed by 20% ethanol precipitation. The CTB is removed by precipitating protein I with ethanol and replaced by N-tetradecyl-N,N-dimethyl-3-ammonia-1-propanesulfonate, a dipolar ionic detergent. Further purification is accomplished by ion-exchange and molecular sieve chromatography. Two species of protein I (34,000 daltons [34K] and 32K) were purified by these methods. The purified proteins reacted with antisera prepared against the homologous organisms. The 34K proteins I generated proteolytic fragments upon treatment with trypsin and chymotrypsin similar to those generated by 34K protein in intact gonococci. The amino acid compositions of the three proteins were much like those of other major proteins of gram-negative organisms.
 ...
PMID:Purification and partial characterization of the major outer membrane protein of Neisseria gonorrhoeae. 680 88

Reovirus is an enteric virus built from eight structural proteins that form a double-layered capsid. During virus entry into cells the reovirus outermost capsid layer (composed of proteins sigma3 and mu1C) is proteolytically processed to generate first an infectious subviral particle (ISVP), then the transcriptionally active core particle. Previous studies have demonstrated that protein sigma3, the outermost protein in the viral capsid, is removed from virus particles extremely rapidly. Other studies, using the detergent tetradecyl sulfate (14SO4) in combination with the protease chymotrypsin, have shown that mu1C cleavage is not necessary for infectious viral processing. We have recently used mass spectrometry to characterize the cascade of sigma3 proteolysis in intact reovirus serotype 1 Lang (T1L) virions (Mendez et al., Virology 2003; 311: 289-304). In the present study, we use high-resolution mass spectrometry to characterize the cascade of outer capsid digestion of both T1L and the other commonly used reovirus strain (serotype 3 Dearing [T3D]), with the protease trypsin, both in the presence and absence of 14SO4. These studies indicate that digestion kinetics and specificities are determined both by virus type and by presence or absence of detergent. Presence of detergent accelerated digestion of both outer capsid proteins. In contrast to chymotrypsin digestion, which segregated sigma3 digestion from mu1 digestion, both proteins were rapidly digested by trypsin in the presence of detergent.
 ...
PMID:High-resolution mass spectrometric mapping of reovirus digestion. 1639 31