The structure of an N-terminal fragment of CD4 has been determined to 2.4 A resolution. It has two tightly abutting domains connected by a continuous beta strand. Both have the immunoglobulin fold, but domain 2 has a truncated beta barrel and a non-standard disulphide bond. The binding sites for monoclonal antibodies, class II major histocompatibility complex molecules, and human immunodeficiency virus gp120 can be mapped on the molecular surface.

Bombesin-like peptides are essential autocrine growth factors for many small cell carcinomas (SCCas) of the lung. Herein, we demonstrate that these malignant pulmonary neuroendocrine cells express low levels of the cell surface metalloendopeptidase CD10/neutral endopeptidase 24.11 (CD10/NEP, common acute lymphoblastic leukemia antigen)

No abstract

The utility of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry for the analysis of C-terminal peptide ladders from carboxypeptidase Y (CPY) digestions is discussed. MALDI analysis of aliquots of an optimized time-dependent CPY digestion of ACTH 7-38 fragment allowed for the sequence of the first 19 amino acids from the C-terminus to be determined in 25 min of digestion time. A strategy for performing parallel concentration-dependent digestions on the MAL-DI plate is proven to be superior to the time-dependent approach as the method development time and practical amounts of both peptide and enzyme consumed are reduced significantly. The on-plate approach offered the same sequence information from the ACTH 7-38 fragment and was used to digest 22 peptides of various amino acid composition, size, charge, and polarity. Of the 22 peptides digested on-plate, sequence information was derived from 19 of them. A statistical analysis strategy for ladder sequencing utilizing t-statistics is offered as a method for placing confidence intervals on residue assignments.

No abstract