Kinetic analysis of the interaction of human tissue kallikrein with single-chain human high and low molecular weight kininogens.

Abstract

Human low molecular weight kininogen (LMWK) and high molecular weight kininogen (HMWK) have been purified to apparent homogeneity as intact, single-chain molecules. When they interacted with homologous urinary kallikrein, 0.9 mol of kinin per mol of substrate was released from LMWK and 0.7 mol of kinin per mol of substrate was released from HMWK. These functionally and structurally intact substrates have been used to obtain the kinetic constants for kinin release by purified human tissue kallikreins. With human urinary kallikrein, -apparent sec- (3,5,(15)(16)(17). Antibody specific for the human HMWK NH2-terminal chain recognizes both HMWK and LMWK, whereas antibody specific for the HMWK COOH-terminal chain recognizes only HMWK (18). Furthermore, the COOH-terminal chains of both bovine and human HMWK exhibit all the procoagulant activity of the intact molecule (2,19,20) whereas human and bovine LMWK lack this activity (10, 20), suggesting that the features that distinguish bovine HMWK and LMWK are also characteristics of human HMWK and LMWK. Glandular (tissue) kallikreins, which are found in kidney, pancreas, and salivary glands and in their secretions, are structurally, functionally, and antigenically different from plasma kallikrein but are related to each other (21-25). Glandular kallikrein has also been identified antigenically in human (26) and rat (27, 28) plasma, and the glandular kallikrein extracted from human plasma by a procedure that included immunoaffinity chromatography cleaved both synthetic substrates and HMWK (29). A single report (30) of the interaction of a glandular kallikrein-human salivary kallikrein-with human kininogen described the time-dependent cleavage of HMWK but did not present a detailed kinetic analysis or describe cleavage of LMWK.The difficulty in purifying LMWK as a fully active molecule free of albumin (31), some a-globulins of similar size and charge (32), and plasminogen (33, 34) has precluded adequate kinetic studies of human LMWK-enzyme interactions. Hence, the previous studies with human LMWK have used partially purified kininogen isolated under denaturing conditions (33,34). Purification of human LMWK to apparent homogeneity by a reproducible six-step procedure (9) and the availability of apparently homogeneous human HMWK (5) and tissue kallikreins (35-37) now permit the comparative kinetic analyses of kininogen cleavage by these enzymes. MATERIALS AND METHODSReagents. Sources were as follows: human albumin (purest), Behringwerke AG (Marburg, Federal Republic of Germany);Abbreviations: HMWK, high molecular weight kininogen; LMWK, low molecular weight kininogen; TAMe, a-N-p-tosyl-L-arginine methyl ester; LBTI, lima bean trypsin inhibitor; iPr2P-F, diisopropylfluorophosphate; BK, bradykinin; HUK, human urinary kallikrein; HPK, human pancreatic kallikrein.

Not More than Three Tissue Kallikreins Identified from Organs of the Guinea Pig

“…Inspite of similar specific activities measured with D-ValLeuArg-pNA, the initial rate of kinin release from bovine L-kininogen by gpK1, the most active guinea pig enzyme, was 7 fold lower than the rate measured for pK1 (Fiedler and Hinz, 1992) and 13-fold lower than that obtained for hK1. The latter value was similar to published kinetic constants (Pierce and Guimaraes, 1976;Geiger et al, 1977;Maier et al, 1983). When each TK was injected into the circulation of guinea pigs, the decrease in blood pressure considered to be due to kinin release from endogenous kininogen was greatest for submandibular gpK1, which had shown the fastest rate of kallidin release from bovine kininogen ( Table 6).…”

Urinary kallikrein excretion during inhibition of endogenous angiotensin II in the pig

“…For example, the decrease in urinary sodium concentration at a MAP of 60 mmHg could be responsible for the decrease of urinary kallikrein at that pressure. Changes in pH may also influence urinary kinin excretion (Diaz et al, 1980), although such an effect on urinary kallikrein has not been described and the enzyme appears to be stable over a wide range of pH (Maier et al, 1983 (Hilton & Lewis, 1955).…”

“…The enzyme urinary kallikrein belongs to a group of serine proteases, termed glandular kallikreins, that release potent vasodilator peptides, kinins, from plasma kininogens (Maier et al, 1983). Glandular kallikreins (tissue kallikreins) are found in a number of organs including the kidney, pancreas, and salivary glands and in their secretions.…”

The Kallikrein-Kininogen-Kinin System in Patients with Liver Disease and Ascites

“…Our patients had a 50% reduction in the excretion of intact kininogen compared to the sodium-matched normals (7.19 vs. 15.52 pg/kinin/day). The concentration of kininogen in urine is well below the Km for the reaction with kallikrein and therefore kininogen excretion is rate limiting for the generation of kinins [4,39], Low molecular weight kininogen, the prefered sub strate for renal kallikrein, is thought to be synthesized in the liver and enters the urine via glomerular filtration [40][41][42]. Renal synthesis of kininogen has been suggested but remains to be confirmed [6].…”