An expanded genetic code facilitates antibody chemical conjugation involving the lambda light chain

The collective immunohistochemical expression of human lysozyme, human alpha-1-antitrypsin, human CD3 antigen, calf vimentin, human keratins, human lambda light chains, canine immunoglobulins IgG, IgM, and bovine protein S-100 has been analyzed on formalin-fixed, paraffin-embedded tissue sections of 25 spontaneous canine transmissible venereal tumors (CTVT) from both genital and extragenital locations using the avidin-biotin-peroxidase complex technique. Lysozyme immunoreactivity was detected in 10/25 CTVT, alpha-1-antitrypsin in 14/25 CTVT, and vimentin in 25/25 CTVT. All CTVT cells were negative to keratins 5 + 8 of the Moll catalogue (RCK-102), S-100 protein, lambda light-chain immunoglobulins, IgG, IgM, and CD3 antigen. The intratumoral T- and B-lymphocyte infiltrate was differentiated using CD3 antigen, lambda light-chain immunoglobulins, IgG, and IgM, and this technique could be useful to evaluate the regressive or progressive growth stage of venereal tumors. Our findings support the hypothesis of a histiocytic immunophenotype for CTVT, and these staining techniques could be used in the differential diagnosis with lymphomas.

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Sequence Communication AL 612, a glycosylated lambda light chain of subgroup I

Amyloid ◽

10.3109/13506120009146825 ◽

2000 ◽

Vol 7 (1) ◽

pp. 51-53

Author(s):

Trine Nilsen ◽

Knut Sletten ◽

Per Westermark

Keyword(s):

Light Chain ◽

Lambda Light Chain

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Measuring the tolerance of the genetic code to altered codon size

10.1101/2021.04.26.441066 ◽

2021 ◽

Author(s):

E. DeBenedictis ◽

D. Söll ◽

K. Esvelt

Keyword(s):

Genetic Code ◽

Protein Translation ◽

Single Amino Acid ◽

Trna Synthetases ◽

E Coli ◽

Aminoacyl Trna Synthetases ◽

Triplet Codon ◽

Orthogonal Set ◽

Expanded Genetic Code ◽

Primordial Earth

SummaryProtein translation using four-base codons occurs in both natural and synthetic systems. What constraints contributed to the universal adoption of a triplet-codon, rather than quadruplet-codon, genetic code? Here, we investigate the tolerance of the E. coli genetic code to tRNA mutations that increase codon size. We found that tRNAs from all twenty canonical isoacceptor classes can be converted to functional quadruplet tRNAs (qtRNAs), many of which selectively incorporate a single amino acid in response to a specified four-base codon. However, efficient quadruplet codon translation often requires multiple tRNA mutations, potentially constraining evolution. Moreover, while tRNAs were largely amenable to quadruplet conversion, only nine of the twenty aminoacyl tRNA synthetases tolerate quadruplet anticodons. These constitute a functional and mutually orthogonal set, but one that sharply limits the chemical alphabet available to a nascent all-quadruplet code. Our results illuminate factors that led to selection and maintenance of triplet codons in primordial Earth and provide a blueprint for synthetic biologists to deliberately engineer an all-quadruplet expanded genetic code.

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