Disease relevance of LOC396897

• A lambda gt11 cDNA library, prepared from porcine submaxillary gland mRNA, was screened with anti-apomucin IgG, and five antibody-reactive phage were isolated [1].

High impact information on LOC396897

• Moreover, immunoblots of apomucin prepared in the presence or the absence of protease inhibitors, with antibodies specific for the half-cystine-rich domains or the tandem repeat sequences, show that the half-cystine-rich domain is absent in apomucin unless protease inhibitors are present throughout [2].
• The molecular weight of undegraded apomucin has not been established exactly, but gel filtration in 6 M guanidine hydrochloride suggests that it is considerably higher than 250,000 [2].
• The amino acid composition of apomucin isolated in the absence of protease inhibitors was shown earlier (Eckhardt, A. E., Timpte, C. S., Abernethy, J. L., Toumadje, A., Johnson, W. C., Jr., and Hill, R. L. (1987) J. Biol. Chem. 282, 11339-11344) to be devoid of half-cystine [2].
• The nucleotide sequence of 1510 bases in the 3.7-kilobase cDNA insert of lambda PSM103 has been established, thereby giving a deduced amino acid sequence of 503 residues in apomucin, or about 45% of the molecule [1].
• Although the sequences around 192 serine and threonine residues have been established in apomucin, a recognition sequence for the N-acetylgalactosaminyltransferase that initiates glycosylation of apomucin is not evident, except that the glycosylated residues occur in turns [1].

Biological context of LOC396897

• Moreover, the peptide was isolated in 760% yield, indicating that the tandem repeat occurs at least eight times in apomucin [1].
• The presence of such a long repetitive region in the gene for apomucin raises the possibility for considerable polymorphism in the gene and a corresponding size heterogeneity of apomucin [1].
• We now describe the complete sequence and genomic organization of the apomucin encoded by 43 exons [3].

Anatomical context of LOC396897

• Porcine submaxillary gland apomucin contains tandemly repeated, identical sequences of 81 residues [1].
• The Golgi apparatus, forming mucous droplets, and mucous droplets contained no apomucin [4].
• Although the rough endoplasmic reticulum contained most of the apomucin in mucous cells, some cisternae of the endoplasmic reticulum and the nuclear envelope were devoid of apomucin [4].

Associations of LOC396897 with chemical compounds

• The molecular weight of apomucin was 96,500 as determined by gel filtration in guanidine hydrochloride [5].
• The resulting apomucin freed of glycosidases was found to contain nine amino acids: threonine, serine, glutamic acid, proline, glycine, alanine, valine, isoleucine, and arginine [5].
• This contrasts with the use of trifluoromethanesulfonic acid (TFMSA), which generates apomucin products of lower molecular weights [6].

Analytical, diagnostic and therapeutic context of LOC396897

• Circular dichroism spectroscopy of apomucin suggests that it contains 42% aperiodic or "other" structure, 40% beta-turns, 10% antiparallel pleated sheet, and 8% helical structures [5].
• Electron microscopy of sections of Lowicryl K4M-embedded tissue reacted successively with antibodies and protein A-gold complexes showed apomucin exclusively in mucous cells within the rough endoplasmic reticulum, transitional elements of the endoplasmic reticulum, and vesicles at the cis side of the Golgi apparatus [4].

References